Hello, syzbot found the following issue on: HEAD commit: bf9f243f23e6 Merge tag '5.15-rc-ksmbd-part2' of git://git... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1537eedd300000 kernel config: https://syzkaller.appspot.com/x/.config?x=37df9ef5660a8387 dashboard link: https://syzkaller.appspot.com/bug?extid=79e3be0f27748965946b compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+79e3be0f27748965946b@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KFENCE: use-after-free read in kvm_fastop_exception+0xf6a/0x1058 Use-after-free read at 0xffff88823bd9e020 (in kfence-#206): kvm_fastop_exception+0xf6a/0x1058 d_lookup+0xd8/0x170 fs/dcache.c:2370 lookup_dcache+0x1e/0x130 fs/namei.c:1520 __lookup_hash+0x29/0x180 fs/namei.c:1543 kern_path_locked+0x17e/0x320 fs/namei.c:2567 handle_remove+0xa2/0x5fe drivers/base/devtmpfs.c:312 handle drivers/base/devtmpfs.c:382 [inline] devtmpfs_work_loop drivers/base/devtmpfs.c:395 [inline] devtmpfsd+0x1b9/0x2a3 drivers/base/devtmpfs.c:437 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 kfence-#206: 0xffff88823bd9e000-0xffff88823bd9efff, size=4096, cache=names_cache allocated by task 22 on cpu 1 at 51.213658s: getname_kernel+0x4e/0x370 fs/namei.c:226 kern_path_locked+0x71/0x320 fs/namei.c:2558 handle_remove+0xa2/0x5fe drivers/base/devtmpfs.c:312 handle drivers/base/devtmpfs.c:382 [inline] devtmpfs_work_loop drivers/base/devtmpfs.c:395 [inline] devtmpfsd+0x1b9/0x2a3 drivers/base/devtmpfs.c:437 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 freed by task 22 on cpu 1 at 51.213995s: putname.part.0+0xe1/0x120 fs/namei.c:270 putname include/linux/err.h:41 [inline] filename_parentat fs/namei.c:2547 [inline] kern_path_locked+0xc2/0x320 fs/namei.c:2558 handle_remove+0xa2/0x5fe drivers/base/devtmpfs.c:312 handle drivers/base/devtmpfs.c:382 [inline] devtmpfs_work_loop drivers/base/devtmpfs.c:395 [inline] devtmpfsd+0x1b9/0x2a3 drivers/base/devtmpfs.c:437 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 CPU: 1 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:kvm_fastop_exception+0xf6a/0x1058 Code: d3 ed e9 bf d9 6e f8 49 8d 0e 48 83 e1 f8 4c 8b 21 41 8d 0e 83 e1 07 c1 e1 03 49 d3 ec e9 15 e7 6e f8 49 8d 4d 00 48 83 e1 f8 <4c> 8b 21 41 8d 4d 00 83 e1 07 c1 e1 03 49 d3 ec e9 05 f1 6e f8 bd RSP: 0018:ffffc90000dcfae8 EFLAGS: 00010282 RAX: 0000000034736376 RBX: ffff88806f127938 RCX: ffff88823bd9e020 RDX: ffffed100de24f2e RSI: 0000000000000004 RDI: 0000000000000007 RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88806f127968 R10: ffffed100de24f2d R11: 0000000000000000 R12: ffff88823bd9e020 R13: ffff88823bd9e020 R14: ffff88806f127968 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff88823bd9e020 CR3: 0000000026259000 CR4: 0000000000350ee0 Call Trace: d_lookup+0xd8/0x170 fs/dcache.c:2370 lookup_dcache+0x1e/0x130 fs/namei.c:1520 __lookup_hash+0x29/0x180 fs/namei.c:1543 kern_path_locked+0x17e/0x320 fs/namei.c:2567 handle_remove+0xa2/0x5fe drivers/base/devtmpfs.c:312 handle drivers/base/devtmpfs.c:382 [inline] devtmpfs_work_loop drivers/base/devtmpfs.c:395 [inline] devtmpfsd+0x1b9/0x2a3 drivers/base/devtmpfs.c:437 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ================================================================== ---------------- Code disassembly (best guess): 0: d3 ed shr %cl,%ebp 2: e9 bf d9 6e f8 jmpq 0xf86ed9c6 7: 49 8d 0e lea (%r14),%rcx a: 48 83 e1 f8 and $0xfffffffffffffff8,%rcx e: 4c 8b 21 mov (%rcx),%r12 11: 41 8d 0e lea (%r14),%ecx 14: 83 e1 07 and $0x7,%ecx 17: c1 e1 03 shl $0x3,%ecx 1a: 49 d3 ec shr %cl,%r12 1d: e9 15 e7 6e f8 jmpq 0xf86ee737 22: 49 8d 4d 00 lea 0x0(%r13),%rcx 26: 48 83 e1 f8 and $0xfffffffffffffff8,%rcx * 2a: 4c 8b 21 mov (%rcx),%r12 <-- trapping instruction 2d: 41 8d 4d 00 lea 0x0(%r13),%ecx 31: 83 e1 07 and $0x7,%ecx 34: c1 e1 03 shl $0x3,%ecx 37: 49 d3 ec shr %cl,%r12 3a: e9 05 f1 6e f8 jmpq 0xf86ef144 3f: bd .byte 0xbd --- 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@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
