syzbot


BUG: sleeping function called from invalid context in ext4_update_super

Status: fixed on 2023/09/28 17:51
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+4acc7d910e617b360859@syzkaller.appspotmail.com
Fix commit: f451fd97dd2b ext4: drop the call to ext4_error() from ext4_get_group_info()
First crash: 356d, last: 356d
Discussions (3)
Title Replies (including bot) Last reply
[GIT PULL] ext4 fixes for 6.4-rc7 1 (1) 2023/06/15 20:55
[PATCH] ext4: Drop the call to ext4_error() from ext4_get_group_info() 2 (2) 2023/06/15 14:59
[syzbot] [ext4?] BUG: sleeping function called from invalid context in ext4_update_super 9 (10) 2023/06/14 19:38

Sample crash report:
EXT4-fs error (device loop4): ext4_get_group_info:331: comm syz-executor.4: invalid group 4294819419
BUG: sleeping function called from invalid context at include/linux/buffer_head.h:404
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 21305, name: syz-executor.4
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
5 locks held by syz-executor.4/21305:
 #0: ffff8880292c8460 (sb_writers#4){.+.+}-{0:0}, at: do_sendfile+0x5fb/0xff0 fs/read_write.c:1253
 #1: ffff8880391da200 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: inode_lock include/linux/fs.h:775 [inline]
 #1: ffff8880391da200 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: ext4_buffered_write_iter+0xaf/0x3a0 fs/ext4/file.c:283
 #2: ffff8880391d9ec8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
 #2: ffff8880391d9ec8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_convert_inline_data_to_extent fs/ext4/inline.c:584 [inline]
 #2: ffff8880391d9ec8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_write_inline_data+0x51d/0x1360 fs/ext4/inline.c:740
 #3: ffff8880391da088 (&ei->i_data_sem){++++}-{3:3}, at: ext4_map_blocks+0x980/0x1cf0 fs/ext4/inode.c:616
 #4: ffff88803944f018 (&bgl->locks[i].lock){+.+.}-{2:2}, at: spin_trylock include/linux/spinlock.h:360 [inline]
 #4: ffff88803944f018 (&bgl->locks[i].lock){+.+.}-{2:2}, at: ext4_lock_group fs/ext4/ext4.h:3407 [inline]
 #4: ffff88803944f018 (&bgl->locks[i].lock){+.+.}-{2:2}, at: ext4_mb_try_best_found+0x1ca/0x5a0 fs/ext4/mballoc.c:2166
Preemption disabled at:
[<0000000000000000>] 0x0
CPU: 0 PID: 21305 Comm: syz-executor.4 Not tainted 6.4.0-rc5-syzkaller-00002-gf8dba31b0a82 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 __might_resched+0x5cf/0x780 kernel/sched/core.c:10153
 lock_buffer include/linux/buffer_head.h:404 [inline]
 ext4_update_super+0x93/0x1230 fs/ext4/super.c:6039
 ext4_commit_super+0xd0/0x4c0 fs/ext4/super.c:6117
 ext4_handle_error+0x5ee/0x8b0 fs/ext4/super.c:676
 __ext4_error+0x277/0x3b0 fs/ext4/super.c:776
 ext4_get_group_info+0x382/0x3e0 fs/ext4/balloc.c:331
 ext4_mb_new_inode_pa+0x89c/0x1300 fs/ext4/mballoc.c:4915
 ext4_mb_try_best_found+0x3a1/0x5a0 fs/ext4/mballoc.c:2171
 ext4_mb_regular_allocator+0x3511/0x3c20 fs/ext4/mballoc.c:2784
 ext4_mb_new_blocks+0xe5f/0x44a0 fs/ext4/mballoc.c:5843
 ext4_alloc_branch fs/ext4/indirect.c:340 [inline]
 ext4_ind_map_blocks+0x10d7/0x29e0 fs/ext4/indirect.c:635
 ext4_map_blocks+0x9e7/0x1cf0 fs/ext4/inode.c:625
 _ext4_get_block+0x238/0x6a0 fs/ext4/inode.c:779
 __block_write_begin_int+0x548/0x1a50 fs/buffer.c:2064
 ext4_try_to_write_inline_data+0x7ed/0x1360 fs/ext4/inline.c:740
 ext4_write_begin+0x290/0x10b0 fs/ext4/inode.c:1147
 ext4_da_write_begin+0x300/0xa40 fs/ext4/inode.c:2893
 generic_perform_write+0x300/0x5e0 mm/filemap.c:3923
 ext4_buffered_write_iter+0x122/0x3a0 fs/ext4/file.c:289
 ext4_file_write_iter+0x1d6/0x1930
 do_iter_write+0x7b1/0xcb0 fs/read_write.c:860
 iter_file_splice_write+0x843/0xfe0 fs/splice.c:795
 do_splice_from fs/splice.c:873 [inline]
 direct_splice_actor+0xe7/0x1c0 fs/splice.c:1039
 splice_direct_to_actor+0x4c4/0xbd0 fs/splice.c:994
 do_splice_direct+0x283/0x3d0 fs/splice.c:1082
 do_sendfile+0x620/0xff0 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f0ff0c8c169
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0ff1944168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f0ff0dabf80 RCX: 00007f0ff0c8c169
RDX: 0000000000000000 RSI: 0000000000000007 RDI: 0000000000000006
RBP: 00007f0ff0ce7ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0001000000201005 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe35f5084f R14: 00007f0ff1944300 R15: 0000000000022000
 </TASK>
BUG: scheduling while atomic: syz-executor.4/21305/0x00000002
5 locks held by syz-executor.4/21305:
 #0: ffff8880292c8460 (sb_writers#4){.+.+}-{0:0}, at: do_sendfile+0x5fb/0xff0 fs/read_write.c:1253
 #1: ffff8880391da200 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: inode_lock include/linux/fs.h:775 [inline]
 #1: ffff8880391da200 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: ext4_buffered_write_iter+0xaf/0x3a0 fs/ext4/file.c:283
 #2: ffff8880391d9ec8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
 #2: ffff8880391d9ec8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_convert_inline_data_to_extent fs/ext4/inline.c:584 [inline]
 #2: ffff8880391d9ec8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_write_inline_data+0x51d/0x1360 fs/ext4/inline.c:740
 #3: ffff8880391da088 (&ei->i_data_sem){++++}-{3:3}, at: ext4_map_blocks+0x980/0x1cf0 fs/ext4/inode.c:616
 #4: ffff88803944f018 (&bgl->locks[i].lock){+.+.}-{2:2}, at: spin_trylock include/linux/spinlock.h:360 [inline]
 #4: ffff88803944f018 (&bgl->locks[i].lock){+.+.}-{2:2}, at: ext4_lock_group fs/ext4/ext4.h:3407 [inline]
 #4: ffff88803944f018 (&bgl->locks[i].lock){+.+.}-{2:2}, at: ext4_mb_try_best_found+0x1ca/0x5a0 fs/ext4/mballoc.c:2166
Modules linked in:
Preemption disabled at:
[<0000000000000000>] 0x0

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/06/06 13:40 upstream f8dba31b0a82 a4ae4f42 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: sleeping function called from invalid context in ext4_update_super
* Struck through repros no longer work on HEAD.