fc_mount fs/namespace.c:1198 [inline] do_new_mount_fc fs/namespace.c:3772 [inline] do_new_mount+0x319/0xdc0 fs/namespace.c:3848 do_mount fs/namespace.c:4181 [inline] __do_sys_mount fs/namespace.c:4397 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4374 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4d1359f3ca Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4d1450be18 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f4d1450bea0 RCX: 00007f4d1359f3ca RDX: 0000200000009600 RSI: 0000200000009640 RDI: 00007f4d1450be60 RBP: 0000200000009600 R08: 00007f4d1450bea0 R09: 0000000000000040 R10: 0000000000000040 R11: 0000000000000246 R12: 0000200000009640 R13: 00007f4d1450be60 R14: 000000000000968d R15: 0000200000000540 Mem-Info: active_anon:3087 inactive_anon:70 isolated_anon:0 active_file:0 inactive_file:39535 isolated_file:0 unevictable:1000 dirty:0 writeback:0 slab_reclaimable:6921 slab_unreclaimable:30908 mapped:10042 shmem:1522 pagetables:693 sec_pagetables:291 bounce:0 kernel_misc_reclaimable:0 free:34110 free_pcp:62 free_cma:0 Node 0 active_anon:4kB inactive_anon:72kB active_file:0kB inactive_file:8kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:16kB dirty:0kB writeback:0kB shmem:0kB shmem_thp:0kB shmem_pmdmapped:0kB anon_thp:0kB kernel_stack:2848kB pagetables:800kB sec_pagetables:1092kB all_unreclaimable? yes Balloon:0kB gpu_active:0kB gpu_reclaim:0kB Node 1 active_anon:12344kB inactive_anon:208kB active_file:0kB inactive_file:158132kB unevictable:4000kB isolated(anon):0kB isolated(file):0kB mapped:40152kB dirty:0kB writeback:0kB shmem:6088kB shmem_thp:0kB shmem_pmdmapped:0kB anon_thp:0kB kernel_stack:7292kB pagetables:1972kB sec_pagetables:72kB all_unreclaimable? no Balloon:0kB gpu_active:0kB gpu_reclaim:0kB Node 0 DMA free:1188kB boost:0kB min:760kB low:948kB high:1136kB reserved_highatomic:0kB free_highatomic:0kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB zspages:0kB present:15992kB managed:15360kB mlocked:0kB bounce:0kB free_pcp:12kB local_pcp:12kB free_cma:0kB lowmem_reserve[]: 0 107 107 107 107 Node 0 DMA32 free:5396kB boost:2048kB min:6040kB low:7036kB high:8032kB reserved_highatomic:0kB free_highatomic:0kB active_anon:8kB inactive_anon:68kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB zspages:0kB present:770052kB managed:109788kB mlocked:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB lowmem_reserve[]: 0 0 0 0 0 Node 1 DMA32 free:129636kB boost:0kB min:34304kB low:42880kB high:51456kB reserved_highatomic:0kB free_highatomic:0kB active_anon:12356kB inactive_anon:208kB active_file:0kB inactive_file:158140kB unevictable:4000kB writepending:0kB zspages:1796kB present:786288kB managed:690816kB mlocked:0kB bounce:0kB free_pcp:284kB local_pcp:284kB free_cma:0kB lowmem_reserve[]: 0 0 0 0 0 Node 0 DMA: 7*4kB (U) 5*8kB (U) 0*16kB 21*32kB (U) 1*64kB (U) 1*128kB (U) 1*256kB (U) 0*512kB 0*1024kB 0*2048kB 0*4096kB = 1188kB Node 0 DMA32: 29*4kB (UME) 22*8kB (UME) 17*16kB (UME) 11*32kB (UME) 14*64kB (UME) 8*128kB (UME) 6*256kB (M) 2*512kB (UM) 0*1024kB 0*2048kB 0*4096kB = 5396kB Node 1 DMA32: 181*4kB (U) 24*8kB (UME) 7*16kB (UME) 113*32kB (UME) 9*64kB (UME) 2*128kB (UE) 1*256kB (M) 2*512kB (UM) 0*1024kB 2*2048kB (UE) 29*4096kB (M) = 129636kB Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB Node 0 hugepages_total=2 hugepages_free=2 hugepages_surp=0 hugepages_size=2048kB Node 1 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB Node 1 hugepages_total=2 hugepages_free=2 hugepages_surp=0 hugepages_size=2048kB 41140 total pagecache pages 85 pages in swap cache Free swap = 107112kB Total swap = 124996kB 393083 pages RAM 0 pages HighMem/MovableOnly 189092 pages reserved 0 pages cma reserved XFS (loop0): Ending clean mount XFS (loop0): Quotacheck needed: Please wait. XFS (loop0): Quotacheck: Done. ============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.0.0/5326 is trying to acquire lock: ffff8880441aa540 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_reclaim_inode fs/xfs/xfs_icache.c:1042 [inline] ffff8880441aa540 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_icwalk_process_inode fs/xfs/xfs_icache.c:1734 [inline] ffff8880441aa540 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_icwalk_ag+0x12b7/0x1980 fs/xfs/xfs_icache.c:1816 but task is already holding lock: ffff8880441a8100 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_ilock_for_iomap fs/xfs/xfs_iomap.c:792 [inline] ffff8880441a8100 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_buffered_write_iomap_begin+0x674/0x2350 fs/xfs/xfs_iomap.c:1825 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&xfs_nondir_ilock_class); lock(&xfs_nondir_ilock_class); *** DEADLOCK *** May be due to missing lock nesting notation locks held by syz.0.0/5326: 5, last CPU#0: #0: ffff88801f2dbb70 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259 #1: ffff888035504460 (sb_writers#11){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline] #1: ffff888035504460 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #2: ffff8880441a8310 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: xfs_ilock+0xee/0x380 fs/xfs/xfs_inode.c:149 #3: ffff8880441a8100 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_ilock_for_iomap fs/xfs/xfs_iomap.c:792 [inline] #3: ffff8880441a8100 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_buffered_write_iomap_begin+0x674/0x2350 fs/xfs/xfs_iomap.c:1825 #4: ffff8880355040e8 (&type->s_umount_key#52){.+.+}-{4:4}, at: super_trylock_shared fs/super.c:688 [inline] #4: ffff8880355040e8 (&type->s_umount_key#52){.+.+}-{4:4}, at: super_cache_scan+0x94/0x500 fs/super.c:213 stack backtrace: CPU: 0 UID: 0 PID: 5326 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_deadlock_bug+0x27a/0x290 kernel/locking/lockdep.c:3057 check_deadlock kernel/locking/lockdep.c:3109 [inline] validate_chain kernel/locking/lockdep.c:3911 [inline] __lock_acquire+0x261c/0x2e50 kernel/locking/lockdep.c:5254 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908 down_write_nested+0x9d/0x210 kernel/locking/rwsem.c:1757 xfs_reclaim_inode fs/xfs/xfs_icache.c:1042 [inline] xfs_icwalk_process_inode fs/xfs/xfs_icache.c:1734 [inline] xfs_icwalk_ag+0x12b7/0x1980 fs/xfs/xfs_icache.c:1816 xfs_icwalk fs/xfs/xfs_icache.c:1864 [inline] xfs_reclaim_inodes_nr+0x1e5/0x260 fs/xfs/xfs_icache.c:1108 super_cache_scan+0x476/0x500 fs/super.c:244 do_shrink_slab+0x6d0/0x10e0 mm/shrinker.c:443 shrink_slab+0xea4/0x1220 mm/shrinker.c:674 shrink_one+0x2a2/0x730 mm/vmscan.c:5119 shrink_many mm/vmscan.c:5180 [inline] lru_gen_shrink_node mm/vmscan.c:5258 [inline] shrink_node+0x35d0/0x3e30 mm/vmscan.c:6247 shrink_zones mm/vmscan.c:6503 [inline] do_try_to_free_pages+0x6a3/0x1990 mm/vmscan.c:6565 try_to_free_pages+0x90a/0xe50 mm/vmscan.c:6804 __perform_reclaim mm/page_alloc.c:4451 [inline] __alloc_pages_direct_reclaim+0x17d/0x360 mm/page_alloc.c:4478 __alloc_pages_slowpath+0x64a/0xec0 mm/page_alloc.c:4939 __alloc_frozen_pages_noprof+0x3f3/0x5a0 mm/page_alloc.c:5449 alloc_pages_mpol+0x21e/0x390 mm/mempolicy.c:2486 alloc_frozen_pages_noprof mm/mempolicy.c:2557 [inline] alloc_pages_noprof+0xb1/0x2b0 mm/mempolicy.c:2577 stack_depot_save_flags+0x738/0x7f0 lib/stackdepot.c:685 kasan_save_stack mm/kasan/common.c:58 [inline] kasan_save_track+0x4f/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x321/0x600 mm/slub.c:5563 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] xfs_iext_alloc_node fs/xfs/libxfs/xfs_iext_tree.c:401 [inline] xfs_iext_alloc_root fs/xfs/libxfs/xfs_iext_tree.c:593 [inline] xfs_iext_insert_raw+0x22e/0x30a0 fs/xfs/libxfs/xfs_iext_tree.c:645 xfs_iext_insert+0x36/0x230 fs/xfs/libxfs/xfs_iext_tree.c:684 xfs_bmap_add_extent_hole_delay+0x4e8/0x850 fs/xfs/xfs_iomap.c:1438 xfs_bmapi_reserve_delalloc+0xc60/0xdb0 fs/xfs/xfs_iomap.c:1557 xfs_buffered_write_iomap_begin+0x18da/0x2350 fs/xfs/xfs_iomap.c:2073 iomap_iter_next include/linux/iomap.h:382 [inline] xfs_buffered_write_iomap_next+0x52c/0x740 fs/xfs/xfs_iomap.c:2177 iomap_iter+0xe2/0xec0 fs/iomap/iter.c:122 iomap_file_buffered_write+0x249/0xb90 fs/iomap/buffered-io.c:1312 xfs_file_buffered_write+0x20a/0x870 fs/xfs/xfs_file.c:1064 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4d1359e159 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4d1450bfe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f4d13825fa0 RCX: 00007f4d1359e159 RDX: 000000000208e24b RSI: 0000200000000000 RDI: 0000000000000006 RBP: 00007f4d13635024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4d13826038 R14: 00007f4d13825fa0 R15: 00007ffc9ee75eb8