Hello, syzbot found the following issue on: HEAD commit: 3fe121b62282 Add linux-next specific files for 20240712 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=1769e695980000 kernel config: https://syzkaller.appspot.com/x/.config?x=98dd8c4bab5cdce dashboard link: https://syzkaller.appspot.com/bug?extid=c0f0941337ade4c26ed1 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/8c6fbf69718d/disk-3fe121b6.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/39fc7e43dfc1/vmlinux-3fe121b6.xz kernel image: https://storage.googleapis.com/syzbot-assets/0a78e70e4b4e/bzImage-3fe121b6.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+c0f0941337ade4c26ed1@xxxxxxxxxxxxxxxxxxxxxxxxx ============================================ WARNING: possible recursive locking detected 6.10.0-rc7-next-20240712-syzkaller #0 Not tainted -------------------------------------------- mount/4518 is trying to acquire lock: ffff88801d2b1498 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock+0x1c/0x60 include/linux/mmap_lock.h:144 but task is already holding lock: ffff88801d2b1498 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:144 [inline] ffff88801d2b1498 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x159/0xc80 mm/mmap.c:3396 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&mm->mmap_lock); lock(&mm->mmap_lock); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by mount/4518: #0: ffff88801d2b1498 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:144 [inline] #0: ffff88801d2b1498 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x159/0xc80 mm/mmap.c:3396 stack backtrace: CPU: 1 UID: 0 PID: 4518 Comm: mount Not tainted 6.10.0-rc7-next-20240712-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3034 check_deadlock kernel/locking/lockdep.c:3086 [inline] validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3888 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5199 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822 down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526 mmap_read_lock+0x1c/0x60 include/linux/mmap_lock.h:144 unmap_single_vma+0x2a0/0x330 mm/memory.c:1832 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1904 exit_mmap+0x264/0xc80 mm/mmap.c:3412 __mmput+0x115/0x390 kernel/fork.c:1347 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x27f0 kernel/exit.c:869 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 __do_sys_exit_group kernel/exit.c:1042 [inline] __se_sys_exit_group kernel/exit.c:1040 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1040 x64_sys_call+0x26c3/0x26d0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd19a876a90 Code: Unable to access opcode bytes at 0x7fd19a876a66. RSP: 002b:00007ffd90b476e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fd19a967860 RCX: 00007fd19a876a90 RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000 RBP: 00007fd19a967860 R08: 00007ffd90b47560 R09: 00007ffd90b47640 R10: 00007ffd90b475a0 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fd19a96b658 R15: 0000000000000001 </TASK> mount (4518) used greatest stack depth: 23680 bytes left --- 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. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title 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
