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: 10595 Comm: syz.1.946 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:zcomp_stream_get+0x26/0xa0 drivers/block/zram/zcomp.c:113 Code: 90 90 90 90 0f 1f 40 d6 41 55 49 bd 00 00 00 00 00 fc ff df 41 54 49 89 fc 55 49 c1 ec 03 48 89 fd 53 4d 01 ec e8 ea 9e cd fb <41> 80 3c 24 00 65 48 8b 1d 25 95 d2 0d 75 4f 48 03 5d 00 31 f6 48 RSP: 0018:ffffc9000d107340 EFLAGS: 00010293 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffffff863aaec6 RDX: ffff88802836dac0 RSI: ffffffff863a5af6 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000006 R09: 6475612f7665642f R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: dffffc0000000000 R14: 6475612f7665642f R15: ffffea0000db97c0 FS: 00007f3b083016c0(0000) GS:ffff888124451000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3b08300f88 CR3: 000000005bc32000 CR4: 00000000003526f0 Call Trace: zram_write_page drivers/block/zram/zram_drv.c:2268 [inline] zram_bvec_write drivers/block/zram/zram_drv.c:2341 [inline] zram_bio_write drivers/block/zram/zram_drv.c:2773 [inline] zram_submit_bio+0xd83/0x1f60 drivers/block/zram/zram_drv.c:2802 __submit_bio+0x419/0x6c0 block/blk-core.c:644 __submit_bio_noacct block/blk-core.c:690 [inline] submit_bio_noacct_nocheck+0x74f/0xc10 block/blk-core.c:755 submit_bio_noacct+0xd17/0x2010 block/blk-core.c:884 blk_crypto_submit_bio include/linux/blk-crypto.h:203 [inline] submit_bh_wbc+0x59c/0x770 fs/buffer.c:2822 __block_write_full_folio+0x77f/0xee0 fs/buffer.c:1931 block_write_full_folio+0x3b5/0x4e0 fs/buffer.c:2751 blkdev_writepages+0xc7/0x150 block/fops.c:487 do_writepages+0x278/0x600 mm/page-writeback.c:2554 filemap_writeback+0x22d/0x2e0 mm/filemap.c:387 filemap_fdatawrite_range mm/filemap.c:412 [inline] file_write_and_wait_range+0xcd/0x140 mm/filemap.c:786 blkdev_fsync+0x6c/0xd0 block/fops.c:620 vfs_fsync_range+0x9b/0x190 fs/sync.c:186 generic_write_sync include/linux/fs.h:2640 [inline] blkdev_write_iter+0x9c3/0xd70 block/fops.c:807 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6ac/0x1070 fs/read_write.c:688 ksys_write+0x12a/0x250 fs/read_write.c:740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3b0739c629 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:00007f3b08301028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f3b07616090 RCX: 00007f3b0739c629 RDX: 000000100000a3d9 RSI: 0000200000000400 RDI: 0000000000000044 RBP: 00007f3b07432b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3b07616128 R14: 00007f3b07616090 R15: 00007ffc93b3b998 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:zcomp_stream_get+0x26/0xa0 drivers/block/zram/zcomp.c:113 Code: 90 90 90 90 0f 1f 40 d6 41 55 49 bd 00 00 00 00 00 fc ff df 41 54 49 89 fc 55 49 c1 ec 03 48 89 fd 53 4d 01 ec e8 ea 9e cd fb <41> 80 3c 24 00 65 48 8b 1d 25 95 d2 0d 75 4f 48 03 5d 00 31 f6 48 RSP: 0018:ffffc9000d107340 EFLAGS: 00010293 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffffff863aaec6 RDX: ffff88802836dac0 RSI: ffffffff863a5af6 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000006 R09: 6475612f7665642f R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: dffffc0000000000 R14: 6475612f7665642f R15: ffffea0000db97c0 FS: 00007f3b083016c0(0000) GS:ffff888124351000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3b082dff88 CR3: 000000005bc32000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess): 0: 90 nop 1: 90 nop 2: 90 nop 3: 90 nop 4: 0f 1f 40 d6 nopl -0x2a(%rax) 8: 41 55 push %r13 a: 49 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%r13 11: fc ff df 14: 41 54 push %r12 16: 49 89 fc mov %rdi,%r12 19: 55 push %rbp 1a: 49 c1 ec 03 shr $0x3,%r12 1e: 48 89 fd mov %rdi,%rbp 21: 53 push %rbx 22: 4d 01 ec add %r13,%r12 25: e8 ea 9e cd fb call 0xfbcd9f14 * 2a: 41 80 3c 24 00 cmpb $0x0,(%r12) <-- trapping instruction 2f: 65 48 8b 1d 25 95 d2 mov %gs:0xdd29525(%rip),%rbx # 0xdd2955c 36: 0d 37: 75 4f jne 0x88 39: 48 03 5d 00 add 0x0(%rbp),%rbx 3d: 31 f6 xor %esi,%esi 3f: 48 rex.W