syzbot


BUG: soft lockup in do_sys_open

Status: upstream: reported C repro on 2021/12/18 10:34
Subsystems: erofs
[Documentation on labels]
Reported-by: syzbot+ebc9ec4cb9279189117a@syzkaller.appspotmail.com
First crash: 908d, last: 519d
Fix bisection: failed (error log, bisect log)
  

Sample crash report:
erofs: read_super, device -> /dev/loop0
erofs: options -> noacl,
watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [syz-executor315:8112]
Modules linked in:
irq event stamp: 6670
hardirqs last  enabled at (6669): [<ffffffff81003ce4>] trace_hardirqs_on_thunk+0x1a/0x1c
hardirqs last disabled at (6670): [<ffffffff81003d00>] trace_hardirqs_off_thunk+0x1a/0x1c
softirqs last  enabled at (1148): [<ffffffff88400678>] __do_softirq+0x678/0x980 kernel/softirq.c:318
softirqs last disabled at (1055): [<ffffffff813927d5>] invoke_softirq kernel/softirq.c:372 [inline]
softirqs last disabled at (1055): [<ffffffff813927d5>] irq_exit+0x215/0x260 kernel/softirq.c:412
CPU: 0 PID: 8112 Comm: syz-executor315 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:vle_get_logical_extent_head drivers/staging/erofs/unzip_vle.c:1543 [inline]
RIP: 0010:z_erofs_map_blocks_iter+0xcac/0x1aa0 drivers/staging/erofs/unzip_vle.c:1666
Code: 18 11 4d 01 e7 e8 64 11 27 fb 44 01 fb 81 e3 ff 0f 00 00 48 03 5c 24 30 48 89 d8 48 89 de 48 c1 e8 03 83 e6 07 42 0f b6 0c 28 <48> 8d 43 01 48 89 c2 48 c1 ea 03 42 0f b6 14 2a 40 38 f1 40 0f 9e
RSP: 0018:ffff8880931af360 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 1ffff11012bb0e9a RBX: ffff888095d874d0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006
RBP: ffff8880a93745c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000006 R11: 0000000000000000 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffea00025761c0 R15: 0000000000000480
FS:  000055555610d300(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffca76d7fe8 CR3: 00000000a4537000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 erofs_map_blocks_iter+0x6d/0x3b0 drivers/staging/erofs/data.c:168
 z_erofs_do_read_page+0x670/0x2820 drivers/staging/erofs/unzip_vle.c:644
 z_erofs_vle_normalaccess_readpage+0x136/0x460 drivers/staging/erofs/unzip_vle.c:1353
 do_read_cache_page+0x533/0x1170 mm/filemap.c:2828
 read_mapping_page include/linux/pagemap.h:402 [inline]
 find_target_block_classic drivers/staging/erofs/namei.c:112 [inline]
 erofs_namei+0x1ab/0x1740 drivers/staging/erofs/namei.c:189
 erofs_lookup+0x143/0x500 drivers/staging/erofs/namei.c:232
 lookup_open+0x698/0x1a20 fs/namei.c:3214
 do_last fs/namei.c:3327 [inline]
 path_openat+0x1804/0x2df0 fs/namei.c:3537
 do_filp_open+0x18c/0x3f0 fs/namei.c:3567
 do_sys_open+0x3b3/0x520 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f8dbaf491f9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 14 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe26112da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007f8dbaf491f9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000200
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007f8dbafb6ec0
R10: 00007ffe26112c70 R11: 0000000000000246 R12: 00007ffe26112dd0
R13: 0000000000000000 R14: 431bde82d7b634db R15: 0000000000000000

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/01/10 20:41 linux-4.19.y 3f8a27f9e27b 48bc529a .config console log report syz C [disk image] [vmlinux] [mounted in repro] ci2-linux-4-19 BUG: soft lockup in do_sys_open
2021/12/18 10:33 linux-4.19.y 3f8a27f9e27b 44068e19 .config console log report syz ci2-linux-4-19 BUG: soft lockup in do_sys_open
2023/01/10 19:30 linux-4.19.y 3f8a27f9e27b 48bc529a .config console log report info [disk image] [vmlinux] ci2-linux-4-19 BUG: soft lockup in do_sys_open
* Struck through repros no longer work on HEAD.