* Re: [syzbot] [usb?] KASAN: slab-use-after-free Read in ep_open [not found] <20260731114022.18295-1-kartikey406@gmail.com> @ 2026-07-31 16:21 ` syzbot 0 siblings, 0 replies; 13+ messages in thread From: syzbot @ 2026-07-31 16:21 UTC (permalink / raw) To: kartikey406, linux-kernel, syzkaller-bugs Hello, syzbot has tested the proposed patch and the reproducer did not trigger any issue: Reported-by: syzbot+df9e891bf8ea586f846b@syzkaller.appspotmail.com Tested-by: syzbot+df9e891bf8ea586f846b@syzkaller.appspotmail.com Tested on: commit: 365f9c7a Merge branches 'for-next/core' and 'for-next/.. git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci console output: https://syzkaller.appspot.com/x/log.txt?x=15bd75b9580000 kernel config: https://syzkaller.appspot.com/x/.config?x=72c97575381cec47 dashboard link: https://syzkaller.appspot.com/bug?extid=df9e891bf8ea586f846b compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 userspace arch: arm64 patch: https://syzkaller.appspot.com/x/patch.diff?x=17a77a49580000 Note: testing is done by a robot and is best-effort only. ^ permalink raw reply [flat|nested] 13+ messages in thread
[parent not found: <20260731080941.13394-1-kartikey406@gmail.com>]
* Re: [syzbot] [usb?] KASAN: slab-use-after-free Read in ep_open [not found] <20260731080941.13394-1-kartikey406@gmail.com> @ 2026-07-31 9:08 ` syzbot 0 siblings, 0 replies; 13+ messages in thread From: syzbot @ 2026-07-31 9:08 UTC (permalink / raw) To: kartikey406, linux-kernel, syzkaller-bugs Hello, syzbot has tested the proposed patch and the reproducer did not trigger any issue: Reported-by: syzbot+df9e891bf8ea586f846b@syzkaller.appspotmail.com Tested-by: syzbot+df9e891bf8ea586f846b@syzkaller.appspotmail.com Tested on: commit: 365f9c7a Merge branches 'for-next/core' and 'for-next/.. git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci console output: https://syzkaller.appspot.com/x/log.txt?x=14c75499580000 kernel config: https://syzkaller.appspot.com/x/.config?x=72c97575381cec47 dashboard link: https://syzkaller.appspot.com/bug?extid=df9e891bf8ea586f846b compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 userspace arch: arm64 patch: https://syzkaller.appspot.com/x/patch.diff?x=152a75b9580000 Note: testing is done by a robot and is best-effort only. ^ permalink raw reply [flat|nested] 13+ messages in thread
[parent not found: <20260731044451.10817-1-kartikey406@gmail.com>]
* Re: [syzbot] [usb?] KASAN: slab-use-after-free Read in ep_open [not found] <20260731044451.10817-1-kartikey406@gmail.com> @ 2026-07-31 6:59 ` syzbot 0 siblings, 0 replies; 13+ messages in thread From: syzbot @ 2026-07-31 6:59 UTC (permalink / raw) To: kartikey406, linux-kernel, syzkaller-bugs Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: KASAN: slab-use-after-free Write in ep_open ================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:112 [inline] BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline] BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:283 [inline] BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:366 [inline] BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:383 [inline] BUG: KASAN: slab-use-after-free in get_ep drivers/usb/gadget/legacy/inode.c:214 [inline] BUG: KASAN: slab-use-after-free in ep_open+0xb8/0x2bc drivers/usb/gadget/legacy/inode.c:831 Write of size 4 at addr ffff0000d322748c by task syz-executor/5557 CPU: 1 UID: 0 PID: 5557 Comm: syz-executor Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 print_address_description+0xb0/0x238 mm/kasan/report.c:378 print_report+0x68/0x84 mm/kasan/report.c:482 kasan_report+0x8c/0xc4 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x17c/0x1ac mm/kasan/generic.c:200 __kasan_check_write+0x20/0x30 mm/kasan/shadow.c:37 instrument_atomic_read_write include/linux/instrumented.h:112 [inline] atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline] __refcount_add include/linux/refcount.h:283 [inline] __refcount_inc include/linux/refcount.h:366 [inline] refcount_inc include/linux/refcount.h:383 [inline] get_ep drivers/usb/gadget/legacy/inode.c:214 [inline] ep_open+0xb8/0x2bc drivers/usb/gadget/legacy/inode.c:831 do_dentry_open+0x5c4/0xfc0 fs/open.c:947 vfs_open+0x44/0x2dc fs/open.c:1052 do_open fs/namei.c:4700 [inline] path_openat+0x21fc/0x2a60 fs/namei.c:4863 do_file_open+0x1c8/0x2e8 fs/namei.c:4892 do_sys_openat2+0x114/0x1e8 fs/open.c:1368 do_sys_open+0xb0/0xe0 fs/open.c:1374 __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __arm64_sys_openat+0xa0/0xbc fs/open.c:1385 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 Allocated by task 5798: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:78 kasan_save_alloc_info+0x44/0x54 mm/kasan/generic.c:570 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x9c/0xb4 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x2e8/0x5ec mm/slub.c:5515 _kmalloc_noprof include/linux/slab.h:969 [inline] _kzalloc_noprof include/linux/slab.h:1290 [inline] activate_ep_files drivers/usb/gadget/legacy/inode.c:1616 [inline] gadgetfs_bind+0x204/0x7a0 drivers/usb/gadget/legacy/inode.c:1708 gadget_bind_driver+0x274/0x834 drivers/usb/gadget/udc/core.c:1662 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x29c/0x800 drivers/base/dd.c:706 __driver_probe_device+0x1e0/0x350 drivers/base/dd.c:868 driver_probe_device+0x6c/0x19c drivers/base/dd.c:898 __driver_attach+0x168/0x384 drivers/base/dd.c:1292 bus_for_each_dev+0x128/0x1b4 drivers/base/bus.c:383 driver_attach+0x50/0x60 drivers/base/dd.c:1310 bus_add_driver+0x208/0x500 drivers/base/bus.c:763 driver_register+0x220/0x310 drivers/base/driver.c:174 usb_gadget_register_driver_owner+0xf0/0x25c drivers/usb/gadget/udc/core.c:1752 dev_config+0x91c/0xcc0 drivers/usb/gadget/legacy/inode.c:1899 vfs_write+0x2a4/0xa0c fs/read_write.c:685 ksys_write+0x12c/0x228 fs/read_write.c:739 __do_sys_write fs/read_write.c:750 [inline] __se_sys_write fs/read_write.c:747 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:747 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 Freed by task 5799: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:78 kasan_save_free_info+0x58/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x74/0xa4 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2705 [inline] slab_free mm/slub.c:6405 [inline] kfree+0x188/0x690 mm/slub.c:6720 put_ep+0xd0/0x144 drivers/usb/gadget/legacy/inode.c:225 destroy_ep_files+0x244/0x2dc drivers/usb/gadget/legacy/inode.c:1597 gadgetfs_unbind+0x114/0x1f0 drivers/usb/gadget/legacy/inode.c:1673 gadget_unbind_driver+0x188/0x790 drivers/usb/gadget/udc/core.c:1724 device_remove+0xc4/0x134 drivers/base/dd.c:616 __device_release_driver drivers/base/dd.c:1349 [inline] device_release_driver_internal+0x124/0x20c drivers/base/dd.c:1372 driver_detach+0x124/0x1b4 drivers/base/dd.c:1435 bus_remove_driver+0x124/0x22c drivers/base/bus.c:832 driver_unregister+0x78/0xac drivers/base/driver.c:202 usb_gadget_unregister_driver+0x50/0x78 drivers/usb/gadget/udc/core.c:1784 dev_release+0x8c/0x15c drivers/usb/gadget/legacy/inode.c:1213 __fput+0x338/0x74c fs/file_table.c:512 ____fput+0x20/0x30 fs/file_table.c:540 task_work_run+0x1cc/0x25c kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x58c/0x1a74 kernel/exit.c:1009 __do_sys_exit kernel/exit.c:1119 [inline] __se_sys_exit kernel/exit.c:1117 [inline] do_group_exit+0x0/0x238 kernel/exit.c:1117 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 The buggy address belongs to the object at ffff0000d3227400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 140 bytes inside of freed 512-byte region [ffff0000d3227400, ffff0000d3227600) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x113224 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x5ffc00000000040(head|node=0|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 05ffc00000000040 ffff0000c0001c80 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 05ffc00000000040 ffff0000c0001c80 dead000000000100 dead000000000122 head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 05ffc00000000002 fffffdffc34c8901 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000d3227380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff0000d3227400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000d3227480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000d3227500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000d3227580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: lib/refcount.c:25 at refcount_warn_saturate+0x134/0x1f8 lib/refcount.c:25, CPU#1: syz-executor/5557 Modules linked in: CPU: 1 UID: 0 PID: 5557 Comm: syz-executor Tainted: G B syzkaller #0 PREEMPT Tainted: [B]=BAD_PAGE Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026 pstate: 634000c5 (nZCv daIF +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : refcount_warn_saturate+0x134/0x1f8 lib/refcount.c:25 lr : refcount_warn_saturate+0x134/0x1f8 lib/refcount.c:25 sp : ffff800094a97740 x29: ffff800094a97740 x28: dfff800000000000 x27: 1fffe00019788600 x26: ffff0000cbc43008 x25: 1fffe0001aebd509 x24: ffff0000d75ea848 x23: dfff800000000000 x22: 0000000000000000 x21: ffff0000cbc42fc0 x20: ffff0000d322748c x19: ffff80008a158000 x18: 0000000000000000 x17: 3d3d3d3d3d3d3d3d x16: 3d3d3d3d3d3d3d3d x15: 3d3d3d3d3d3d3d3d x14: 3d3d3d3d3d3d3d3d x13: 0000000000000001 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000000003 x9 : 360a90020a0ce000 x8 : 360a90020a0ce000 x7 : 0000000000000001 x6 : ffff80008048de94 x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff8000802f8054 x2 : 0000000100000001 x1 : ffff0000c2a03a80 x0 : 0000000000000000 Call trace: refcount_warn_saturate+0x134/0x1f8 lib/refcount.c:25 (P) __refcount_add include/linux/refcount.h:-1 [inline] __refcount_inc include/linux/refcount.h:366 [inline] refcount_inc include/linux/refcount.h:383 [inline] get_ep drivers/usb/gadget/legacy/inode.c:214 [inline] ep_open+0x238/0x2bc drivers/usb/gadget/legacy/inode.c:831 do_dentry_open+0x5c4/0xfc0 fs/open.c:947 vfs_open+0x44/0x2dc fs/open.c:1052 do_open fs/namei.c:4700 [inline] path_openat+0x21fc/0x2a60 fs/namei.c:4863 do_file_open+0x1c8/0x2e8 fs/namei.c:4892 do_sys_openat2+0x114/0x1e8 fs/open.c:1368 do_sys_open+0xb0/0xe0 fs/open.c:1374 __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __arm64_sys_openat+0xa0/0xbc fs/open.c:1385 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 irq event stamp: 217440 hardirqs last enabled at (217439): [<ffff800080b9d9d8>] kasan_quarantine_put+0xb4/0x1c4 mm/kasan/quarantine.c:234 hardirqs last disabled at (217440): [<ffff8000869050fc>] __raw_spin_lock_irq include/linux/spinlock_api_smp.h:140 [inline] hardirqs last disabled at (217440): [<ffff8000869050fc>] _raw_spin_lock_irq+0x28/0x70 kernel/locking/spinlock.c:174 softirqs last enabled at (213442): [<ffff80008013c0b4>] local_bh_enable include/linux/bottom_half.h:33 [inline] softirqs last enabled at (213442): [<ffff80008013c0b4>] put_cpu_fpsimd_context arch/arm64/kernel/fpsimd.c:251 [inline] softirqs last enabled at (213442): [<ffff80008013c0b4>] fpsimd_restore_current_state+0x39c/0x9c8 arch/arm64/kernel/fpsimd.c:1797 softirqs last disabled at (213440): [<ffff80008013bd5c>] local_bh_disable include/linux/bottom_half.h:20 [inline] softirqs last disabled at (213440): [<ffff80008013bd5c>] get_cpu_fpsimd_context arch/arm64/kernel/fpsimd.c:234 [inline] softirqs last disabled at (213440): [<ffff80008013bd5c>] fpsimd_restore_current_state+0x44/0x9c8 arch/arm64/kernel/fpsimd.c:1790 ---[ end trace 0000000000000000 ]--- Tested on: commit: 365f9c7a Merge branches 'for-next/core' and 'for-next/.. git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci console output: https://syzkaller.appspot.com/x/log.txt?x=114978c6580000 kernel config: https://syzkaller.appspot.com/x/.config?x=72c97575381cec47 dashboard link: https://syzkaller.appspot.com/bug?extid=df9e891bf8ea586f846b compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 userspace arch: arm64 patch: https://syzkaller.appspot.com/x/patch.diff?x=12b475b9580000 ^ permalink raw reply [flat|nested] 13+ messages in thread
[parent not found: <20260731042637.9137-1-kartikey406@gmail.com>]
* Re: [syzbot] [usb?] KASAN: slab-use-after-free Read in ep_open [not found] <20260731042637.9137-1-kartikey406@gmail.com> @ 2026-07-31 5:42 ` syzbot 0 siblings, 0 replies; 13+ messages in thread From: syzbot @ 2026-07-31 5:42 UTC (permalink / raw) To: kartikey406, linux-kernel, syzkaller-bugs Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: BUG: unable to handle kernel paging request in ep_open Unable to handle kernel paging request at virtual address dfff800000000003 KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] Mem abort info: ESR = 0x0000000096000005 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x05: level 1 translation fault Data abort info: ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0 [dfff800000000003] address between user and kernel address ranges Internal error: Oops: 0000000096000005 [#1] SMP Modules linked in: CPU: 0 UID: 0 PID: 5115 Comm: syz-executor Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026 pstate: 234000c5 (nzCv daIF +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : kasan_byte_accessible+0x10/0x20 mm/kasan/generic.c:210 lr : __kasan_check_byte+0x20/0x54 mm/kasan/common.c:573 sp : ffff800092f37660 x29: ffff800092f37660 x28: ffff800088b0a000 x27: ffff0000c79d57c0 x26: a6d980008690513c x25: 0000000000000000 x24: 0000000000000001 x23: 0000000000000000 x22: 0000000000000018 x21: 0000000000000018 x20: 0000000000000000 x19: ffff80008690513c x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 00000000ffff8000 x13: 0000000000000001 x12: 0000000000000000 x11: ffff800080156ee8 x10: 0000000000000003 x9 : dfff800000000000 x8 : 0000000000000003 x7 : 0000000000000000 x6 : ffff8000836dc930 x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000 x2 : 0000000000000000 x1 : ffff80008690513c x0 : 0000000000000018 Call trace: kasan_mem_to_shadow include/linux/kasan.h:65 [inline] (P) kasan_byte_accessible+0x10/0x20 mm/kasan/generic.c:210 (P) kasan_check_byte include/linux/kasan.h:402 [inline] lock_acquire+0xa4/0x364 kernel/locking/lockdep.c:5842 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock_irq+0x58/0x70 kernel/locking/spinlock.c:174 spin_lock_irq include/linux/spinlock.h:372 [inline] ep_open+0x70/0x2ec drivers/usb/gadget/legacy/inode.c:824 do_dentry_open+0x5c4/0xfc0 fs/open.c:947 vfs_open+0x44/0x2dc fs/open.c:1052 do_open fs/namei.c:4700 [inline] path_openat+0x21fc/0x2a60 fs/namei.c:4863 do_file_open+0x1c8/0x2e8 fs/namei.c:4892 do_sys_openat2+0x114/0x1e8 fs/open.c:1368 do_sys_open+0xb0/0xe0 fs/open.c:1374 __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __arm64_sys_openat+0xa0/0xbc fs/open.c:1385 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 Code: d503245f d343fc08 d2d00009 f2fbffe9 (38696908) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: d503245f bti c 4: d343fc08 lsr x8, x0, #3 8: d2d00009 mov x9, #0x800000000000 // #140737488355328 c: f2fbffe9 movk x9, #0xdfff, lsl #48 * 10: 38696908 ldrb w8, [x8, x9] <-- trapping instruction Tested on: commit: 365f9c7a Merge branches 'for-next/core' and 'for-next/.. git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci console output: https://syzkaller.appspot.com/x/log.txt?x=174c8c9e580000 kernel config: https://syzkaller.appspot.com/x/.config?x=72c97575381cec47 dashboard link: https://syzkaller.appspot.com/bug?extid=df9e891bf8ea586f846b compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 userspace arch: arm64 patch: https://syzkaller.appspot.com/x/patch.diff?x=1176caea580000 ^ permalink raw reply [flat|nested] 13+ messages in thread
* [syzbot] [usb?] KASAN: slab-use-after-free Read in ep_open @ 2026-07-31 1:28 syzbot 2026-08-17 13:42 ` syzbot 0 siblings, 1 reply; 13+ messages in thread From: syzbot @ 2026-07-31 1:28 UTC (permalink / raw) To: gregkh, linux-kernel, linux-usb, syzkaller-bugs Hello, syzbot found the following issue on: HEAD commit: 365f9c7a6b81 Merge branches 'for-next/core' and 'for-next/.. git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci console output: https://syzkaller.appspot.com/x/log.txt?x=13731632580000 kernel config: https://syzkaller.appspot.com/x/.config?x=72c97575381cec47 dashboard link: https://syzkaller.appspot.com/bug?extid=df9e891bf8ea586f846b compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 userspace arch: arm64 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=136d6499580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=138d6449580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/eafe0adb7386/disk-365f9c7a.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/29422d607579/vmlinux-365f9c7a.xz kernel image: https://storage.googleapis.com/syzbot-assets/98ca955a8b54/Image-365f9c7a.gz.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+df9e891bf8ea586f846b@syzkaller.appspotmail.com ================================================================== BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:625 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock+0x130/0xf14 kernel/locking/mutex.c:821 Read of size 8 at addr ffff0000efe3d058 by task syz-executor/5909 CPU: 1 UID: 0 PID: 5909 Comm: syz-executor Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 print_address_description+0xb0/0x238 mm/kasan/report.c:378 print_report+0x68/0x84 mm/kasan/report.c:482 kasan_report+0x8c/0xc4 mm/kasan/report.c:595 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381 __mutex_lock_common kernel/locking/mutex.c:625 [inline] __mutex_lock+0x130/0xf14 kernel/locking/mutex.c:821 mutex_lock_interruptible_nested+0x24/0x30 kernel/locking/mutex.c:899 ep_open+0x58/0x25c drivers/usb/gadget/legacy/inode.c:823 do_dentry_open+0x5c4/0xfc0 fs/open.c:947 vfs_open+0x44/0x2dc fs/open.c:1052 do_open fs/namei.c:4700 [inline] path_openat+0x21fc/0x2a60 fs/namei.c:4863 do_file_open+0x1c8/0x2e8 fs/namei.c:4892 do_sys_openat2+0x114/0x1e8 fs/open.c:1368 do_sys_open+0xb0/0xe0 fs/open.c:1374 __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __arm64_sys_openat+0xa0/0xbc fs/open.c:1385 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 Allocated by task 6282: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:78 kasan_save_alloc_info+0x44/0x54 mm/kasan/generic.c:570 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x9c/0xb4 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x2e8/0x5ec mm/slub.c:5515 _kmalloc_noprof include/linux/slab.h:969 [inline] _kzalloc_noprof include/linux/slab.h:1290 [inline] activate_ep_files drivers/usb/gadget/legacy/inode.c:1601 [inline] gadgetfs_bind+0x204/0x75c drivers/usb/gadget/legacy/inode.c:1692 gadget_bind_driver+0x274/0x834 drivers/usb/gadget/udc/core.c:1662 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x29c/0x800 drivers/base/dd.c:706 __driver_probe_device+0x1e0/0x350 drivers/base/dd.c:868 driver_probe_device+0x6c/0x19c drivers/base/dd.c:898 __driver_attach+0x168/0x384 drivers/base/dd.c:1292 bus_for_each_dev+0x128/0x1b4 drivers/base/bus.c:383 driver_attach+0x50/0x60 drivers/base/dd.c:1310 bus_add_driver+0x208/0x500 drivers/base/bus.c:763 driver_register+0x220/0x310 drivers/base/driver.c:174 usb_gadget_register_driver_owner+0xf0/0x25c drivers/usb/gadget/udc/core.c:1752 dev_config+0x91c/0xcc0 drivers/usb/gadget/legacy/inode.c:1883 vfs_write+0x2a4/0xa0c fs/read_write.c:685 ksys_write+0x12c/0x228 fs/read_write.c:739 __do_sys_write fs/read_write.c:750 [inline] __se_sys_write fs/read_write.c:747 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:747 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 Freed by task 6283: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:78 kasan_save_free_info+0x58/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x74/0xa4 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2705 [inline] slab_free mm/slub.c:6405 [inline] kfree+0x188/0x690 mm/slub.c:6720 put_ep+0xd0/0x144 drivers/usb/gadget/legacy/inode.c:225 destroy_ep_files+0x244/0x2dc drivers/usb/gadget/legacy/inode.c:1582 gadgetfs_unbind+0x114/0x1f0 drivers/usb/gadget/legacy/inode.c:1655 gadget_unbind_driver+0x188/0x790 drivers/usb/gadget/udc/core.c:1724 device_remove+0xc4/0x134 drivers/base/dd.c:616 __device_release_driver drivers/base/dd.c:1349 [inline] device_release_driver_internal+0x124/0x20c drivers/base/dd.c:1372 driver_detach+0x124/0x1b4 drivers/base/dd.c:1435 bus_remove_driver+0x124/0x22c drivers/base/bus.c:832 driver_unregister+0x78/0xac drivers/base/driver.c:202 usb_gadget_unregister_driver+0x50/0x78 drivers/usb/gadget/udc/core.c:1784 dev_release+0x8c/0x15c drivers/usb/gadget/legacy/inode.c:1198 __fput+0x338/0x74c fs/file_table.c:512 ____fput+0x20/0x30 fs/file_table.c:540 task_work_run+0x1cc/0x25c kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x58c/0x1a74 kernel/exit.c:1009 __do_sys_exit kernel/exit.c:1119 [inline] __se_sys_exit kernel/exit.c:1117 [inline] do_group_exit+0x0/0x238 kernel/exit.c:1117 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 The buggy address belongs to the object at ffff0000efe3d000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 88 bytes inside of freed 512-byte region [ffff0000efe3d000, ffff0000efe3d200) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff0000efe3dc00 pfn:0x12fe3c --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [syzbot] [usb?] KASAN: slab-use-after-free Read in ep_open 2026-07-31 1:28 syzbot @ 2026-08-17 13:42 ` syzbot 2026-08-17 15:04 ` Jens Axboe 0 siblings, 1 reply; 13+ messages in thread From: syzbot @ 2026-08-17 13:42 UTC (permalink / raw) To: asml.silence, axboe, brauner, gregkh, io-uring, jack, kartikey406, kees, linux-kernel, linux-usb, mjguzik, nogikh, stern, syzbot, syzbot, syzkaller-bugs, syzkaller-upstream-moderation, torvalds, viro syzbot has bisected this issue to: commit aa00f67adc2c0d6439f81b5a81ff181377c47a7e Author: Jens Axboe <axboe@kernel.dk> Date: Tue Oct 22 19:47:00 2024 +0000 io_uring: add support for fixed wait regions bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=10e60679580000 start commit: 9a143525f62b Merge tag 'ata-7.2-rc7' of git://git.kernel.o.. git tree: upstream final oops: https://syzkaller.appspot.com/x/report.txt?x=12e60679580000 console output: https://syzkaller.appspot.com/x/log.txt?x=14e60679580000 kernel config: https://syzkaller.appspot.com/x/.config?x=c44651ea7dd2f307 dashboard link: https://syzkaller.appspot.com/bug?extid=df9e891bf8ea586f846b syz repro: https://syzkaller.appspot.com/x/repro.syz?x=120defb9580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16323fb9580000 Reported-by: syzbot+df9e891bf8ea586f846b@syzkaller.appspotmail.com Fixes: aa00f67adc2c ("io_uring: add support for fixed wait regions") For information about bisection process see: https://goo.gl/tpsmEJ#bisection ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [syzbot] [usb?] KASAN: slab-use-after-free Read in ep_open 2026-08-17 13:42 ` syzbot @ 2026-08-17 15:04 ` Jens Axboe 2026-08-17 15:45 ` Alan Stern 0 siblings, 1 reply; 13+ messages in thread From: Jens Axboe @ 2026-08-17 15:04 UTC (permalink / raw) To: syzbot, asml.silence, brauner, gregkh, io-uring, jack, kartikey406, kees, linux-kernel, linux-usb, mjguzik, nogikh, stern, syzbot, syzbot, syzkaller-bugs, syzkaller-upstream-moderation, torvalds, viro On 8/17/26 7:42 AM, syzbot wrote: > syzbot has bisected this issue to: > > commit aa00f67adc2c0d6439f81b5a81ff181377c47a7e > Author: Jens Axboe <axboe@kernel.dk> > Date: Tue Oct 22 19:47:00 2024 +0000 > > io_uring: add support for fixed wait regions > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=10e60679580000 > start commit: 9a143525f62b Merge tag 'ata-7.2-rc7' of git://git.kernel.o.. > git tree: upstream > final oops: https://syzkaller.appspot.com/x/report.txt?x=12e60679580000 > console output: https://syzkaller.appspot.com/x/log.txt?x=14e60679580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=c44651ea7dd2f307 > dashboard link: https://syzkaller.appspot.com/bug?extid=df9e891bf8ea586f846b > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=120defb9580000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16323fb9580000 > > Reported-by: syzbot+df9e891bf8ea586f846b@syzkaller.appspotmail.com > Fixes: aa00f67adc2c ("io_uring: add support for fixed wait regions") That looks like nonsense, I strongly suspect it's a race and hence your bisection ends up being mostly useless as it sends you in random directions. -- Jens Axboe ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [syzbot] [usb?] KASAN: slab-use-after-free Read in ep_open 2026-08-17 15:04 ` Jens Axboe @ 2026-08-17 15:45 ` Alan Stern 2026-08-17 16:38 ` syzbot 0 siblings, 1 reply; 13+ messages in thread From: Alan Stern @ 2026-08-17 15:45 UTC (permalink / raw) To: Jens Axboe Cc: syzbot, asml.silence, brauner, gregkh, io-uring, jack, kartikey406, kees, linux-kernel, linux-usb, mjguzik, nogikh, syzbot, syzbot, syzkaller-bugs, syzkaller-upstream-moderation, torvalds, viro On Mon, Aug 17, 2026 at 09:04:06AM -0600, Jens Axboe wrote: > On 8/17/26 7:42 AM, syzbot wrote: > > syzbot has bisected this issue to: > > > > commit aa00f67adc2c0d6439f81b5a81ff181377c47a7e > > Author: Jens Axboe <axboe@kernel.dk> > > Date: Tue Oct 22 19:47:00 2024 +0000 > > > > io_uring: add support for fixed wait regions > > > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=10e60679580000 > > start commit: 9a143525f62b Merge tag 'ata-7.2-rc7' of git://git.kernel.o.. > > git tree: upstream > > final oops: https://syzkaller.appspot.com/x/report.txt?x=12e60679580000 > > console output: https://syzkaller.appspot.com/x/log.txt?x=14e60679580000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=c44651ea7dd2f307 > > dashboard link: https://syzkaller.appspot.com/bug?extid=df9e891bf8ea586f846b > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=120defb9580000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16323fb9580000 > > > > Reported-by: syzbot+df9e891bf8ea586f846b@syzkaller.appspotmail.com > > Fixes: aa00f67adc2c ("io_uring: add support for fixed wait regions") > > That looks like nonsense, I strongly suspect it's a race and hence your > bisection ends up being mostly useless as it sends you in random directions. Agreed. The patch below has already been sent to the USB mailing list. Has syzbot tested it? Alan Stern #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ v7.2 From: Aleksandr Nogikh <nogikh@google.com> A race condition exists between opening a gadgetfs endpoint file and the destruction of the endpoint files, leading to a use-after-free of the ep_data object. When an endpoint file is opened, the VFS looks up the dentry and calls ep_open(). ep_open() retrieves the ep_data pointer from inode->i_private and attempts to lock its mutex. Concurrently, if the gadget is unbound, destroy_ep_files() iterates over the endpoints, unhashes their dentries, and immediately calls put_ep(). This drops the initial reference to the ep_data object, freeing it. If another thread is already in the process of opening the file, it holds a reference to the dentry and the inode. The inode remains alive, and its i_private pointer still points to the now-freed ep_data. When ep_open() proceeds to lock data->lock, it accesses freed memory. BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:625 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock+0x130/0xf14 kernel/locking/mutex.c:821 Read of size 8 at addr ffff0000f43acc58 by task syz-executor/5900 Call trace: __mutex_lock_common kernel/locking/mutex.c:625 [inline] __mutex_lock+0x130/0xf14 kernel/locking/mutex.c:821 mutex_lock_interruptible_nested+0x24/0x30 kernel/locking/mutex.c:899 ep_open+0x58/0x25c drivers/usb/gadget/legacy/inode.c:823 do_dentry_open+0x5c4/0xfc0 fs/open.c:947 vfs_open+0x44/0x2dc fs/open.c:1052 Freed by task 6138: kfree+0x188/0x690 mm/slub.c:6692 put_ep+0xd0/0x144 drivers/usb/gadget/legacy/inode.c:225 destroy_ep_files+0x244/0x2dc drivers/usb/gadget/legacy/inode.c:1582 gadgetfs_unbind+0x114/0x1f0 drivers/usb/gadget/legacy/inode.c:1655 gadget_unbind_driver+0x188/0x790 drivers/usb/gadget/udc/core.c:1724 To fix this, tie the base reference of ep_data to the lifetime of the inode rather than manually dropping it in destroy_ep_files(). Add an .evict_inode callback to gadget_fs_operations that drops the reference when the inode is finally destroyed. Remove the premature put_ep() call from destroy_ep_files(). Additionally, to prevent a double-free in the error path of activate_ep_files(), clear inode->i_private in gadgetfs_create_file() before calling iput() if simple_start_creating() fails. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Assisted-by: Gemini:gemini-3.5-flash Gemini:gemini-3.1-pro-preview syzbot Reported-by: syzbot+df9e891bf8ea586f846b@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=df9e891bf8ea586f846b Link: https://syzkaller.appspot.com/ai_job?id=ae49a838-5eb9-4227-93a3-56ad2313483a Signed-off-by: Aleksandr Nogikh <nogikh@google.com> --- diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c index d87a8ab51..a03062986 100644 --- a/drivers/usb/gadget/legacy/inode.c +++ b/drivers/usb/gadget/legacy/inode.c @@ -1579,8 +1579,6 @@ static void destroy_ep_files (struct dev_data *dev) /* break link to dcache */ simple_remove_by_name(dev->sb->s_root, ep->name, NULL); - put_ep (ep); - spin_lock_irq (&dev->lock); } spin_unlock_irq (&dev->lock); @@ -1996,6 +1994,7 @@ static int gadgetfs_create_file (struct super_block *sb, char const *name, dentry = simple_start_creating(sb->s_root, name); if (IS_ERR(dentry)) { + inode->i_private = NULL; iput(inode); return PTR_ERR(dentry); } @@ -2006,9 +2005,18 @@ static int gadgetfs_create_file (struct super_block *sb, char const *name, return 0; } +static void gadgetfs_evict_inode(struct inode *inode) +{ + truncate_inode_pages_final(&inode->i_data); + clear_inode(inode); + if (inode->i_private && inode->i_fop == &ep_io_operations) + put_ep(inode->i_private); +} + static const struct super_operations gadget_fs_operations = { .statfs = simple_statfs, .drop_inode = inode_just_drop, + .evict_inode = gadgetfs_evict_inode, }; static int base-commit: f5098b6bae761e346ebcd9da7f95622c04733cff -- See https://goo.gle/syzbot-ai-patches for information about AI-generated patches. You can comment on the patch as usual, syzbot will try to address the comments and send a new version of the patch if necessary. syzbot engineers can be reached at syzkaller@googlegroups.com. ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [syzbot] [usb?] KASAN: slab-use-after-free Read in ep_open 2026-08-17 15:45 ` Alan Stern @ 2026-08-17 16:38 ` syzbot 2026-08-17 18:14 ` Alan Stern 0 siblings, 1 reply; 13+ messages in thread From: syzbot @ 2026-08-17 16:38 UTC (permalink / raw) To: asml.silence, axboe, brauner, gregkh, io-uring, jack, kartikey406, kees, linux-kernel, linux-usb, mjguzik, nogikh, stern, syzbot, syzbot, syzkaller-bugs, syzkaller-upstream-moderation, torvalds, viro Hello, syzbot has tested the proposed patch and the reproducer did not trigger any issue: Reported-by: syzbot+df9e891bf8ea586f846b@syzkaller.appspotmail.com Tested-by: syzbot+df9e891bf8ea586f846b@syzkaller.appspotmail.com Tested on: commit: 8d3ae592 Linux 7.2 git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ v7.2 console output: https://syzkaller.appspot.com/x/log.txt?x=16a91a25580000 kernel config: https://syzkaller.appspot.com/x/.config?x=c44651ea7dd2f307 dashboard link: https://syzkaller.appspot.com/bug?extid=df9e891bf8ea586f846b compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 patch: https://syzkaller.appspot.com/x/patch.diff?x=15790679580000 Note: testing is done by a robot and is best-effort only. ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [syzbot] [usb?] KASAN: slab-use-after-free Read in ep_open 2026-08-17 16:38 ` syzbot @ 2026-08-17 18:14 ` Alan Stern 2026-08-18 7:42 ` Greg KH 0 siblings, 1 reply; 13+ messages in thread From: Alan Stern @ 2026-08-17 18:14 UTC (permalink / raw) To: Greg KH Cc: syzbot, asml.silence, axboe, brauner, io-uring, jack, kartikey406, kees, linux-kernel, linux-usb, mjguzik, nogikh, syzbot, syzbot, syzkaller-bugs, syzkaller-upstream-moderation, torvalds, viro On Mon, Aug 17, 2026 at 09:38:02AM -0700, syzbot wrote: > Hello, > > syzbot has tested the proposed patch and the reproducer did not trigger any issue: > > Reported-by: syzbot+df9e891bf8ea586f846b@syzkaller.appspotmail.com > Tested-by: syzbot+df9e891bf8ea586f846b@syzkaller.appspotmail.com > > Tested on: > > commit: 8d3ae592 Linux 7.2 > git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ v7.2 > console output: https://syzkaller.appspot.com/x/log.txt?x=16a91a25580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=c44651ea7dd2f307 > dashboard link: https://syzkaller.appspot.com/bug?extid=df9e891bf8ea586f846b > compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 > patch: https://syzkaller.appspot.com/x/patch.diff?x=15790679580000 > > Note: testing is done by a robot and is best-effort only. Greg: Has this patch ever been queued? https://lore.kernel.org/linux-usb/ee41fbfd-f368-4a06-95d6-ae9b4267fd82@mail.kernel.org/ Looks like you can add syzbot's Tested-by: tag, as well as my Acked-by:. Note that a different patch to fix the same problem was submitted here: https://lore.kernel.org/linux-usb/20260731230603.4637-1-kartikey406@gmail.com/ IMO the first patch above is superior. Alan Stern ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [syzbot] [usb?] KASAN: slab-use-after-free Read in ep_open 2026-08-17 18:14 ` Alan Stern @ 2026-08-18 7:42 ` Greg KH 2026-08-18 15:37 ` Alan Stern 0 siblings, 1 reply; 13+ messages in thread From: Greg KH @ 2026-08-18 7:42 UTC (permalink / raw) To: Alan Stern Cc: syzbot, asml.silence, axboe, brauner, io-uring, jack, kartikey406, kees, linux-kernel, linux-usb, mjguzik, nogikh, syzbot, syzbot, syzkaller-bugs, syzkaller-upstream-moderation, torvalds, viro On Mon, Aug 17, 2026 at 02:14:17PM -0400, Alan Stern wrote: > On Mon, Aug 17, 2026 at 09:38:02AM -0700, syzbot wrote: > > Hello, > > > > syzbot has tested the proposed patch and the reproducer did not trigger any issue: > > > > Reported-by: syzbot+df9e891bf8ea586f846b@syzkaller.appspotmail.com > > Tested-by: syzbot+df9e891bf8ea586f846b@syzkaller.appspotmail.com > > > > Tested on: > > > > commit: 8d3ae592 Linux 7.2 > > git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ v7.2 > > console output: https://syzkaller.appspot.com/x/log.txt?x=16a91a25580000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=c44651ea7dd2f307 > > dashboard link: https://syzkaller.appspot.com/bug?extid=df9e891bf8ea586f846b > > compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 > > patch: https://syzkaller.appspot.com/x/patch.diff?x=15790679580000 > > > > Note: testing is done by a robot and is best-effort only. > > Greg: > > Has this patch ever been queued? > > https://lore.kernel.org/linux-usb/ee41fbfd-f368-4a06-95d6-ae9b4267fd82@mail.kernel.org/ No because it looks like there are competing patches here as you point out. > Looks like you can add syzbot's Tested-by: tag, as well as my Acked-by:. > > Note that a different patch to fix the same problem was submitted here: > > https://lore.kernel.org/linux-usb/20260731230603.4637-1-kartikey406@gmail.com/ > > IMO the first patch above is superior. So Aleksandr's patch should be applied and not Deepanshu's? thanks, greg k-h ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [syzbot] [usb?] KASAN: slab-use-after-free Read in ep_open 2026-08-18 7:42 ` Greg KH @ 2026-08-18 15:37 ` Alan Stern 2026-08-19 12:26 ` Greg KH 0 siblings, 1 reply; 13+ messages in thread From: Alan Stern @ 2026-08-18 15:37 UTC (permalink / raw) To: Greg KH Cc: syzbot, asml.silence, axboe, brauner, io-uring, jack, kartikey406, kees, linux-kernel, linux-usb, mjguzik, nogikh, syzbot, syzbot, syzkaller-bugs, syzkaller-upstream-moderation, torvalds, viro On Tue, Aug 18, 2026 at 09:42:34AM +0200, Greg KH wrote: > On Mon, Aug 17, 2026 at 02:14:17PM -0400, Alan Stern wrote: > > Greg: > > > > Has this patch ever been queued? > > > > https://lore.kernel.org/linux-usb/ee41fbfd-f368-4a06-95d6-ae9b4267fd82@mail.kernel.org/ > > No because it looks like there are competing patches here as you point > out. > > > Looks like you can add syzbot's Tested-by: tag, as well as my Acked-by:. > > > > Note that a different patch to fix the same problem was submitted here: > > > > https://lore.kernel.org/linux-usb/20260731230603.4637-1-kartikey406@gmail.com/ > > > > IMO the first patch above is superior. > > So Aleksandr's patch should be applied and not Deepanshu's? That's my recommendation. You can take a quick look at the two patches and see what you think. We haven't heard back from Deepanshu. Aleksandr doesn't seem to have strong feelings either way. Alan Stern ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [syzbot] [usb?] KASAN: slab-use-after-free Read in ep_open 2026-08-18 15:37 ` Alan Stern @ 2026-08-19 12:26 ` Greg KH 0 siblings, 0 replies; 13+ messages in thread From: Greg KH @ 2026-08-19 12:26 UTC (permalink / raw) To: Alan Stern Cc: syzbot, asml.silence, axboe, brauner, io-uring, jack, kartikey406, kees, linux-kernel, linux-usb, mjguzik, nogikh, syzbot, syzbot, syzkaller-bugs, syzkaller-upstream-moderation, torvalds, viro On Tue, Aug 18, 2026 at 11:37:16AM -0400, Alan Stern wrote: > On Tue, Aug 18, 2026 at 09:42:34AM +0200, Greg KH wrote: > > On Mon, Aug 17, 2026 at 02:14:17PM -0400, Alan Stern wrote: > > > Greg: > > > > > > Has this patch ever been queued? > > > > > > https://lore.kernel.org/linux-usb/ee41fbfd-f368-4a06-95d6-ae9b4267fd82@mail.kernel.org/ > > > > No because it looks like there are competing patches here as you point > > out. > > > > > Looks like you can add syzbot's Tested-by: tag, as well as my Acked-by:. > > > > > > Note that a different patch to fix the same problem was submitted here: > > > > > > https://lore.kernel.org/linux-usb/20260731230603.4637-1-kartikey406@gmail.com/ > > > > > > IMO the first patch above is superior. > > > > So Aleksandr's patch should be applied and not Deepanshu's? > > That's my recommendation. You can take a quick look at the two patches > and see what you think. > > We haven't heard back from Deepanshu. Aleksandr doesn't seem to have > strong feelings either way. Aleksandr's patch is much more simple, and relies on the reference counting logic in the inode itself, instead of "hand rolling" it like Deepanshu's does. I'll take it after -rc1 is out. As this is a syzbot-only type of thing, there's no rush here. thanks, greg k-h ^ permalink raw reply [flat|nested] 13+ messages in thread
end of thread, other threads:[~2026-08-19 12:27 UTC | newest]
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