Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 UID: 0 PID: 26029 Comm: syz.1.2925 Tainted: G U I L syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [I]=FIRMWARE_WORKAROUND, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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 4a 56 cb fb e8 45 56 cb fb 65 48 8b 1d 85 2b bf 0d <41> 80 3c 24 00 75 4f 48 03 5d 00 31 f6 48 89 df e8 e8 3f 84 05 48
RSP: 0018:ffffc90005067490 EFLAGS: 00010287
RAX: 0000000000000871 RBX: ffff8881248fc000 RCX: ffffc90018ede000
RDX: 0000000000080000 RSI: ffffffff85f3149b RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000006 R09: 746d2f636f72702f
R10: 0000000000000000 R11: ffff88802d9f0b30 R12: dffffc0000000000
R13: dffffc0000000000 R14: 746d2f636f72702f R15: ffffea000122a380
FS: 00007fc9ee5f86c0(0000) GS:ffff8881248fc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32cfbff8 CR3: 0000000076b0e000 CR4: 00000000003526f0
Call Trace:
<TASK>
zram_write_page drivers/block/zram/zram_drv.c:2124 [inline]
zram_bvec_write drivers/block/zram/zram_drv.c:2197 [inline]
zram_bio_write drivers/block/zram/zram_drv.c:2638 [inline]
zram_submit_bio+0xde2/0x1e10 drivers/block/zram/zram_drv.c:2667
__submit_bio+0x304/0x690 block/blk-core.c:646
__submit_bio_noacct block/blk-core.c:692 [inline]
submit_bio_noacct_nocheck+0x72f/0xbe0 block/blk-core.c:757
submit_bio_noacct+0x5bd/0x1f40 block/blk-core.c:879
submit_bio_wait+0x110/0x250 block/bio.c:1391
__blkdev_direct_IO_simple+0x488/0x860 block/fops.c:99
blkdev_direct_IO+0xcb8/0x1fe0 block/fops.c:431
blkdev_direct_write block/fops.c:723 [inline]
blkdev_write_iter+0x703/0xe00 block/fops.c:791
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/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc9ed78f7c9
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:00007fc9ee5f8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fc9ed9e6090 RCX: 00007fc9ed78f7c9
RDX: 000000100000a3d9 RSI: 0000200000000400 RDI: 0000000000000009
RBP: 00007fc9ed813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc9ed9e6128 R14: 00007fc9ed9e6090 R15: 00007ffeef4b4218
</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 4a 56 cb fb e8 45 56 cb fb 65 48 8b 1d 85 2b bf 0d <41> 80 3c 24 00 75 4f 48 03 5d 00 31 f6 48 89 df e8 e8 3f 84 05 48
RSP: 0018:ffffc90005067490 EFLAGS: 00010287
RAX: 0000000000000871 RBX: ffff8881248fc000 RCX: ffffc90018ede000
RDX: 0000000000080000 RSI: ffffffff85f3149b RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000006 R09: 746d2f636f72702f
R10: 0000000000000000 R11: ffff88802d9f0b30 R12: dffffc0000000000
R13: dffffc0000000000 R14: 746d2f636f72702f R15: ffffea000122a380
FS: 00007fc9ee5f86c0(0000) GS:ffff8881248fc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa5a2002e9c CR3: 0000000076b0e000 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 4a 56 cb fb call 0xfbcb5661
17: e8 45 56 cb fb call 0xfbcb5661
1c: 65 48 8b 1d 85 2b bf mov %gs:0xdbf2b85(%rip),%rbx # 0xdbf2ba9
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 e8 3f 84 05 call 0x5844021
39: 48 rex.W