syzbot has found a reproducer for the following issue on: HEAD commit: 591cd61541b9 Add linux-next specific files for 20221207 git tree: linux-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=1044bbad880000 kernel config: https://syzkaller.appspot.com/x/.config?x=8b2d3e63e054c24f dashboard link: https://syzkaller.appspot.com/bug?extid=38a94e1872470e3450a6 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15236fe3880000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=178313f3880000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/bc862c01ec56/disk-591cd615.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/8f9b93f8ed2f/vmlinux-591cd615.xz kernel image: https://storage.googleapis.com/syzbot-assets/9d5cb636d548/bzImage-591cd615.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+38a94e1872470e3450a6@xxxxxxxxxxxxxxxxxxxxxxxxx ============================================ WARNING: possible recursive locking detected 6.1.0-rc8-next-20221207-syzkaller #0 Not tainted -------------------------------------------- syz-executor169/5069 is trying to acquire lock: ffff8880750fa480 (&ovl_i_mutex_key[depth]){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline] ffff8880750fa480 (&ovl_i_mutex_key[depth]){+.+.}-{3:3}, at: ovl_remove_privs_unlocked fs/overlayfs/file.c:519 [inline] ffff8880750fa480 (&ovl_i_mutex_key[depth]){+.+.}-{3:3}, at: ovl_fallocate+0x15c/0x270 fs/overlayfs/file.c:546 but task is already holding lock: ffff8880750fa480 (&ovl_i_mutex_key[depth]){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline] ffff8880750fa480 (&ovl_i_mutex_key[depth]){+.+.}-{3:3}, at: ovl_fallocate+0x9f/0x270 fs/overlayfs/file.c:535 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&ovl_i_mutex_key[depth]); lock(&ovl_i_mutex_key[depth]); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by syz-executor169/5069: #0: ffff88802b1d6460 (sb_writers#9){.+.+}-{0:0}, at: ksys_fallocate fs/open.c:346 [inline] #0: ffff88802b1d6460 (sb_writers#9){.+.+}-{0:0}, at: __do_sys_fallocate fs/open.c:354 [inline] #0: ffff88802b1d6460 (sb_writers#9){.+.+}-{0:0}, at: __se_sys_fallocate fs/open.c:352 [inline] #0: ffff88802b1d6460 (sb_writers#9){.+.+}-{0:0}, at: __x64_sys_fallocate+0xd3/0x140 fs/open.c:352 #1: ffff8880750fa480 (&ovl_i_mutex_key[depth]){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline] #1: ffff8880750fa480 (&ovl_i_mutex_key[depth]){+.+.}-{3:3}, at: ovl_fallocate+0x9f/0x270 fs/overlayfs/file.c:535 stack backtrace: CPU: 1 PID: 5069 Comm: syz-executor169 Not tainted 6.1.0-rc8-next-20221207-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2990 [inline] check_deadlock kernel/locking/lockdep.c:3033 [inline] validate_chain kernel/locking/lockdep.c:3818 [inline] __lock_acquire.cold+0x116/0x3a7 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 down_write+0x94/0x220 kernel/locking/rwsem.c:1562 inode_lock include/linux/fs.h:756 [inline] ovl_remove_privs_unlocked fs/overlayfs/file.c:519 [inline] ovl_fallocate+0x15c/0x270 fs/overlayfs/file.c:546 vfs_fallocate+0x48b/0xe00 fs/open.c:323 ksys_fallocate fs/open.c:346 [inline] __do_sys_fallocate fs/open.c:354 [inline] __se_sys_fallocate fs/open.c:352 [inline] __x64_sys_fallocate+0xd3/0x140 fs/open.c:352 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fa3d1605c29 Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffccc67e118 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa3d1605c29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007fa3d15c9dd0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000001000f4 R11: 0000000000000246 R12: 00007fa3d15c9e60 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK>
