Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 UID: 0 PID: 9063 Comm: syz.2.572 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:zcomp_stream_get+0x33/0xa0 drivers/block/zram/zcomp.c:113
Code: 00 00 00 00 fc ff df 41 54 55 48 89 fd 53 49 89 ec 49 c1 ec 03 4d 01 ec e8 ca 87 99 fb e8 c5 87 99 fb 65 48 8b 1d c5 dd b4 0d <41> 80 3c 24 00 75 4f 48 03 5d 00 31 f6 48 89 df e8 48 c9 71 05 48
RSP: 0018:ffffc90003237498 EFLAGS: 00010287
RAX: 0000000000000739 RBX: ffff8881247ba000 RCX: ffffc90017801000
RDX: 0000000000080000 RSI: ffffffff8621825b RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888026d23400 R15: ffffea0001dc9400
FS: 00007feb56baf6c0(0000) GS:ffff8881247ba000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32921ff8 CR3: 000000007d4fc000 CR4: 00000000003526f0
Call Trace:
<TASK>
zram_write_page drivers/block/zram/zram_drv.c:1866 [inline]
zram_bvec_write drivers/block/zram/zram_drv.c:1939 [inline]
zram_bio_write drivers/block/zram/zram_drv.c:2380 [inline]
zram_submit_bio+0xdd4/0x1df0 drivers/block/zram/zram_drv.c:2409
__submit_bio+0x304/0x690 block/blk-core.c:644
__submit_bio_noacct block/blk-core.c:690 [inline]
submit_bio_noacct_nocheck+0x852/0xd30 block/blk-core.c:753
submit_bio_noacct+0xc20/0x1ed0 block/blk-core.c:874
submit_bio_wait+0x110/0x250 block/bio.c:1367
__blkdev_direct_IO_simple+0x431/0x800 block/fops.c:92
blkdev_direct_IO+0xc59/0x2030 block/fops.c:428
blkdev_direct_write block/fops.c:719 [inline]
blkdev_write_iter+0x703/0xe00 block/fops.c:787
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x7d3/0x11d0 fs/read_write.c:686
ksys_write+0x12a/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feb55d8ec29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007feb56baf038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007feb55fd5fa0 RCX: 00007feb55d8ec29
RDX: 000000100000a3d9 RSI: 0000200000000400 RDI: 0000000000000003
RBP: 00007feb55e11e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007feb55fd6038 R14: 00007feb55fd5fa0 R15: 00007ffdf96b7a38
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:zcomp_stream_get+0x33/0xa0 drivers/block/zram/zcomp.c:113
Code: 00 00 00 00 fc ff df 41 54 55 48 89 fd 53 49 89 ec 49 c1 ec 03 4d 01 ec e8 ca 87 99 fb e8 c5 87 99 fb 65 48 8b 1d c5 dd b4 0d <41> 80 3c 24 00 75 4f 48 03 5d 00 31 f6 48 89 df e8 48 c9 71 05 48
RSP: 0018:ffffc90003237498 EFLAGS: 00010287
RAX: 0000000000000739 RBX: ffff8881247ba000 RCX: ffffc90017801000
RDX: 0000000000080000 RSI: ffffffff8621825b RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888026d23400 R15: ffffea0001dc9400
FS: 00007feb56baf6c0(0000) GS:ffff8881247ba000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d219ff8 CR3: 000000007d4fc000 CR4: 00000000003526f0
----------------
Code disassembly (best guess), 6 bytes skipped:
0: df 41 54 filds 0x54(%rcx)
3: 55 push %rbp
4: 48 89 fd mov %rdi,%rbp
7: 53 push %rbx
8: 49 89 ec mov %rbp,%r12
b: 49 c1 ec 03 shr $0x3,%r12
f: 4d 01 ec add %r13,%r12
12: e8 ca 87 99 fb call 0xfb9987e1
17: e8 c5 87 99 fb call 0xfb9987e1
1c: 65 48 8b 1d c5 dd b4 mov %gs:0xdb4ddc5(%rip),%rbx # 0xdb4dde9
23: 0d
* 24: 41 80 3c 24 00 cmpb $0x0,(%r12) <-- trapping instruction
29: 75 4f jne 0x7a
2b: 48 03 5d 00 add 0x0(%rbp),%rbx
2f: 31 f6 xor %esi,%esi
31: 48 89 df mov %rbx,%rdi
34: e8 48 c9 71 05 call 0x571c981
39: 48 rex.W