syzbot


BUG: unable to handle kernel paging request in ext4_quota_read

Status: upstream: reported syz repro on 2023/05/24 10:35
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+157b8930f5de4714c2a6@syzkaller.appspotmail.com
First crash: 388d, last: 356d
Bug presence (2)
Date Name Commit Repro Result
2023/05/24 linux-6.1.y (ToT) fa74641fb6b9 C [report] INFO: rcu detected stall in corrupted
2023/05/24 upstream (ToT) 9d646009f65d C Didn't crash
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in ext4_quota_read ext4 syz 2 354d 351d 0/27 auto-obsoleted due to no activity on 2023/10/04 17:21
Fix bisection attempts (1)
Created Duration User Patch Repo Result
2023/09/01 17:42 1h54m fix candidate upstream job log (0)

Sample crash report:
Unable to handle kernel paging request at virtual address dfff80000000000a
KASAN: null-ptr-deref in range [0x0000000000000050-0x0000000000000057]
Mem abort info:
  ESR = 0x0000000096000006
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x06: level 2 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000006
  CM = 0, WnR = 0
[dfff80000000000a] address between user and kernel address ranges
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 16451 Comm: syz-executor.2 Not tainted 6.1.29-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : i_size_read include/linux/fs.h:864 [inline]
pc : ext4_quota_read+0xb4/0x294 fs/ext4/super.c:7072
lr : ext4_quota_read+0xac/0x294 fs/ext4/super.c:7067
sp : ffff800020a16e90
x29: ffff800020a16ea0 x28: 0000000000000400 x27: dfff800000000000
x26: dfff800000000000 x25: 0000000000000050 x24: 000000000000000c
x23: ffff0000cc036000 x22: 0000000000000400 x21: 0000000000000400
x20: 0000000000000000 x19: ffff0000c89f4000 x18: 1ffff00004142e64
x17: ffff80001559d000 x16: ffff80001203ab40 x15: 0000000000000000
x14: 00000000120e89bc x13: 00000000a5ae9b40 x12: 0000000000000000
x11: ff80800008f370a0 x10: 0000000000000000 x9 : ffff800008f370a0
x8 : 000000000000000a x7 : 0000000000000000 x6 : 000000000000003f
x5 : 0000000000000040 x4 : 0000000000000400 x3 : 0000000000000400
x2 : ffff0000c89f4000 x1 : 000000000000000c x0 : 0000000000000040
Call trace:
 i_size_read include/linux/fs.h:864 [inline]
 ext4_quota_read+0xb4/0x294 fs/ext4/super.c:7072
 read_blk fs/quota/quota_tree.c:55 [inline]
 do_insert_tree+0x1c4/0x1474 fs/quota/quota_tree.c:347
 dq_insert_tree fs/quota/quota_tree.c:401 [inline]
 qtree_write_dquot+0x318/0x488 fs/quota/quota_tree.c:420
 v2_write_dquot+0xf4/0x188 fs/quota/quota_v2.c:358
 dquot_acquire+0x2c4/0x5c4 fs/quota/dquot.c:444
 ext4_acquire_dquot+0x270/0x398 fs/ext4/super.c:6762
 dqget+0x844/0xc48 fs/quota/dquot.c:914
 __dquot_initialize+0x344/0xb54 fs/quota/dquot.c:1492
 dquot_initialize fs/quota/dquot.c:1550 [inline]
 dquot_file_open+0x90/0xc8 fs/quota/dquot.c:2181
 ext4_file_open+0x200/0x540 fs/ext4/file.c:893
 do_dentry_open+0x734/0xfa0 fs/open.c:882
 vfs_open+0x7c/0x90 fs/open.c:1013
 do_open fs/namei.c:3557 [inline]
 path_openat+0x1e14/0x2548 fs/namei.c:3714
 do_filp_open+0x1bc/0x3cc fs/namei.c:3741
 do_sys_openat2+0x128/0x3d8 fs/open.c:1310
 do_sys_open fs/open.c:1326 [inline]
 __do_sys_openat fs/open.c:1342 [inline]
 __se_sys_openat fs/open.c:1337 [inline]
 __arm64_sys_openat+0x1f0/0x240 fs/open.c:1337
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581
Code: 54000ea8 97d70fc1 91014299 d343ff28 (387b6908) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	54000ea8 	b.hi	0x1d4  // b.pmore
   4:	97d70fc1 	bl	0xffffffffff5c3f08
   8:	91014299 	add	x25, x20, #0x50
   c:	d343ff28 	lsr	x8, x25, #3
* 10:	387b6908 	ldrb	w8, [x8, x27] <-- trapping instruction

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/05/24 10:34 linux-6.1.y fa74641fb6b9 4bce1a3e .config console log report syz [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in ext4_quota_read
2023/06/25 01:56 linux-6.1.y e84a4e368abe 79782afc .config console log report syz [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan general protection fault in ext4_quota_read
* Struck through repros no longer work on HEAD.