Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.15' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 27.126444] EXT4-fs (loop0): mounted filesystem without journal. Opts: ,errors=continue [ 27.137065] [ 27.138705] ====================================================== [ 27.145005] WARNING: possible circular locking dependency detected [ 27.151396] 4.14.276-syzkaller #0 Not tainted [ 27.155874] ------------------------------------------------------ [ 27.162172] syz-executor197/7982 is trying to acquire lock: [ 27.167851] (&ei->xattr_sem){++++}, at: [] ext4_xattr_get+0x107/0x8b0 [ 27.176059] [ 27.176059] but task is already holding lock: [ 27.181997] (&ea_inode->i_rwsem#10/1){+.+.}, at: [] chown_common+0x272/0x4b0 [ 27.190813] [ 27.190813] which lock already depends on the new lock. [ 27.190813] [ 27.199128] [ 27.199128] the existing dependency chain (in reverse order) is: [ 27.206718] [ 27.206718] -> #1 (&ea_inode->i_rwsem#10/1){+.+.}: [ 27.213118] down_write+0x34/0x90 [ 27.217066] ext4_xattr_set_entry+0x258a/0x3180 [ 27.222226] ext4_xattr_ibody_set+0x73/0x280 [ 27.227126] ext4_xattr_set_handle+0x518/0xda0 [ 27.232198] ext4_xattr_set+0x118/0x230 [ 27.236672] __vfs_setxattr+0xdc/0x130 [ 27.241052] __vfs_setxattr_noperm+0xfd/0x3d0 [ 27.246040] __vfs_setxattr_locked+0x14d/0x250 [ 27.251116] vfs_setxattr+0xcf/0x230 [ 27.255321] setxattr+0x1a9/0x300 [ 27.259265] path_setxattr+0x118/0x130 [ 27.263644] SyS_setxattr+0x36/0x50 [ 27.267764] do_syscall_64+0x1d5/0x640 [ 27.272143] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 27.277820] [ 27.277820] -> #0 (&ei->xattr_sem){++++}: [ 27.283423] lock_acquire+0x170/0x3f0 [ 27.287717] down_read+0x36/0x80 [ 27.291668] ext4_xattr_get+0x107/0x8b0 [ 27.296135] __vfs_getxattr+0xb9/0x100 [ 27.300515] cap_inode_need_killpriv+0x3c/0x50 [ 27.305591] security_inode_need_killpriv+0x66/0xa0 [ 27.311097] notify_change+0x7d7/0xd10 [ 27.315476] chown_common+0x40b/0x4b0 [ 27.319825] SyS_fchownat+0xf6/0x190 [ 27.324033] do_syscall_64+0x1d5/0x640 [ 27.328412] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 27.334167] [ 27.334167] other info that might help us debug this: [ 27.334167] [ 27.342279] Possible unsafe locking scenario: [ 27.342279] [ 27.348663] CPU0 CPU1 [ 27.353305] ---- ---- [ 27.357947] lock(&ea_inode->i_rwsem#10/1); [ 27.362334] lock(&ei->xattr_sem); [ 27.368452] lock(&ea_inode->i_rwsem#10/1); [ 27.375493] lock(&ei->xattr_sem); [ 27.379091] [ 27.379091] *** DEADLOCK *** [ 27.379091] [ 27.385128] 2 locks held by syz-executor197/7982: [ 27.389937] #0: (sb_writers#3){.+.+}, at: [] mnt_want_write+0x3a/0xb0 [ 27.398235] #1: (&ea_inode->i_rwsem#10/1){+.+.}, at: [] chown_common+0x272/0x4b0 [ 27.407484] [ 27.407484] stack backtrace: [ 27.411950] CPU: 1 PID: 7982 Comm: syz-executor197 Not tainted 4.14.276-syzkaller #0 [ 27.419808] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.429137] Call Trace: [ 27.431700] dump_stack+0x1b2/0x281 [ 27.435301] print_circular_bug.constprop.0.cold+0x2d7/0x41e [ 27.441073] __lock_acquire+0x2e0e/0x3f20 [ 27.445194] ? check_usage_backwards+0x2c0/0x2c0 [ 27.449922] ? trace_hardirqs_on+0x10/0x10 [ 27.454135] ? check_preemption_disabled+0x35/0x240 [ 27.459125] ? __lock_acquire+0x2190/0x3f20 [ 27.463420] lock_acquire+0x170/0x3f0 [ 27.467194] ? ext4_xattr_get+0x107/0x8b0 [ 27.471313] down_read+0x36/0x80 [ 27.474653] ? ext4_xattr_get+0x107/0x8b0 [ 27.478771] ext4_xattr_get+0x107/0x8b0 [ 27.482730] ? current_time+0x16/0xb0 [ 27.486502] ? ext4_xattr_ibody_get+0x510/0x510 [ 27.491153] ? xattr_resolve_name+0x22c/0x370 [ 27.495620] ? ext4_xattr_security_set+0x40/0x40 [ 27.500348] __vfs_getxattr+0xb9/0x100 [ 27.504208] ? __vfs_setxattr+0x130/0x130 [ 27.508329] ? put_timespec64+0xf0/0xf0 [ 27.512279] ? current_kernel_time64+0x154/0x230 [ 27.517007] cap_inode_need_killpriv+0x3c/0x50 [ 27.521562] security_inode_need_killpriv+0x66/0xa0 [ 27.526549] notify_change+0x7d7/0xd10 [ 27.530409] chown_common+0x40b/0x4b0 [ 27.534181] ? chmod_common+0x390/0x390 [ 27.538405] ? __mnt_want_write+0x1da/0x270 [ 27.542720] SyS_fchownat+0xf6/0x190 [ 27.546682] ? SyS_chmod+0x20/0x20 [ 27.550198] ? do_syscall_64+0x4c/0x640 [ 27.554148] ? SyS_chmod+0x20/0x20 [ 27.557668] do_syscall_64+0x1d5/0x640 [ 27.561568] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 27.566732] RIP: 0033:0x7f5d23e20109 [ 27.570417] RSP: 002b:00007fff191c3c98 EFLAGS: 00000246 ORIG_RAX: 0000000000000104 [ 27.