erofs: (device loop2): mounted with root inode @ nid 36.
erofs: (device loop2): z_erofs_extent_lookback: bogus lookback distance @ nid 36
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 10c641067 P4D 10c641067 PUD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 481 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc90000c96b88 EFLAGS: 00010246
RAX: 1ffffffff0a7bfce RBX: ffffc90000c974e0 RCX: ffff888116c73b40
RDX: 0000000000000000 RSI: ffffc90000c974e0 RDI: ffffc90000c97040
RBP: ffffc90000c96bb0 R08: ffffc90000c9706f R09: ffffc90000c9706a
R10: dffffc0000000000 R11: fffff52000192e0e R12: dffffc0000000000
R13: 000000000000073b R14: ffffc90000c97040 R15: ffffffff853dfe70
FS:  00007fc065f796c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000011692a000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 z_erofs_decompress+0x79/0xb0 fs/erofs/decompressor.c:360
 z_erofs_decompress_pcluster fs/erofs/zdata.c:1110 [inline]
 z_erofs_decompress_queue+0x10ff/0x1a90 fs/erofs/zdata.c:1188
 z_erofs_runqueue+0x11fe/0x1280 fs/erofs/zdata.c:-1
 z_erofs_readpage+0x225/0x500 fs/erofs/zdata.c:1533
 do_read_cache_page+0x69b/0xaa0 mm/filemap.c:-1
 read_cache_page+0x50/0x70 mm/filemap.c:3296
 read_mapping_page include/linux/pagemap.h:498 [inline]
 find_target_block_classic fs/erofs/namei.c:104 [inline]
 erofs_namei+0x162/0x10d0 fs/erofs/namei.c:184
 erofs_lookup+0xa5/0x260 fs/erofs/namei.c:228
 __lookup_slow+0x2b8/0x410 fs/namei.c:1648
 lookup_slow+0x57/0x70 fs/namei.c:1665
 walk_component+0x325/0x460 fs/namei.c:1960
 link_path_walk+0x5b2/0xba0 fs/namei.c:-1
 path_openat+0x27c/0x31c0 fs/namei.c:3513
 do_filp_open+0x1e2/0x410 fs/namei.c:3544
 do_sys_openat2+0x19f/0x750 fs/open.c:1219
 do_sys_open fs/open.c:1235 [inline]
 __do_sys_open fs/open.c:1243 [inline]
 __se_sys_open fs/open.c:1239 [inline]
 __x64_sys_open+0x11c/0x140 fs/open.c:1239
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fc066114ef9
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:00007fc065f79028 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007fc06637ffa0 RCX: 00007fc066114ef9
RDX: 0000000000000000 RSI: 00000000001a1342 RDI: 0000200000000000
RBP: 00007fc0661a9ee0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc066380038 R14: 00007fc06637ffa0 R15: 00007fff3a939238
Modules linked in:
CR2: 0000000000000000
---[ end trace 25dbb0d959e24df6 ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc90000c96b88 EFLAGS: 00010246
RAX: 1ffffffff0a7bfce RBX: ffffc90000c974e0 RCX: ffff888116c73b40
RDX: 0000000000000000 RSI: ffffc90000c974e0 RDI: ffffc90000c97040
RBP: ffffc90000c96bb0 R08: ffffc90000c9706f R09: ffffc90000c9706a
R10: dffffc0000000000 R11: fffff52000192e0e R12: dffffc0000000000
R13: 000000000000073b R14: ffffc90000c97040 R15: ffffffff853dfe70
FS:  00007fc065f796c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000011692a000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400