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: 10669 Comm: syz.3.857 Not tainted 6.16.0-syzkaller-06699-ge8d780dcd957 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:strcmp+0x39/0xb0 lib/string.c:283 Code: df 41 54 55 53 48 89 fb 48 83 ec 08 eb 08 40 84 ed 74 61 4c 89 e6 48 89 df 48 83 c3 01 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 <42> 0f b6 04 28 38 d0 7f 04 84 c0 75 58 48 89 f0 48 89 f2 0f b6 6b RSP: 0018:ffffc90002f477c0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffc9000e822000 RDX: 0000000000000000 RSI: ffffffff8c43e580 RDI: 0000000000000000 RBP: ffffffff8c43d520 R08: 0000000000000001 R09: ffffed1004c45209 R10: ffff88802622904f R11: 0000000000000001 R12: ffff888032d3a000 R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000000 FS: 00007f20fbfaf6c0(0000) GS:ffff88812482c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2c900ff8 CR3: 0000000059abe000 CR4: 00000000003526f0 Call Trace: zcomp_available_show+0x73/0x130 drivers/block/zram/zcomp.c:98 __comp_algorithm_show drivers/block/zram/zram_drv.c:1234 [inline] comp_algorithm_show+0x98/0xd0 drivers/block/zram/zram_drv.c:1391 dev_attr_show+0x53/0xe0 drivers/base/core.c:2421 sysfs_kf_seq_show+0x213/0x3e0 fs/sysfs/file.c:65 seq_read_iter+0x506/0x12c0 fs/seq_file.c:230 kernfs_fop_read_iter+0x40f/0x5a0 fs/kernfs/file.c:279 copy_splice_read+0x615/0xba0 fs/splice.c:363 do_splice_read fs/splice.c:979 [inline] do_splice_read+0x285/0x370 fs/splice.c:953 splice_direct_to_actor+0x2a1/0xa30 fs/splice.c:1083 do_splice_direct_actor fs/splice.c:1201 [inline] do_splice_direct+0x174/0x240 fs/splice.c:1227 do_sendfile+0xb06/0xe50 fs/read_write.c:1370 __do_sys_sendfile64 fs/read_write.c:1431 [inline] __se_sys_sendfile64 fs/read_write.c:1417 [inline] __x64_sys_sendfile64+0x1d8/0x220 fs/read_write.c:1417 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f20fb18e9a9 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:00007f20fbfaf038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f20fb3b6160 RCX: 00007f20fb18e9a9 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000003 RBP: 00007f20fb210d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000007 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f20fb3b6160 R15: 00007ffd602412c8 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:strcmp+0x39/0xb0 lib/string.c:283 Code: df 41 54 55 53 48 89 fb 48 83 ec 08 eb 08 40 84 ed 74 61 4c 89 e6 48 89 df 48 83 c3 01 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 <42> 0f b6 04 28 38 d0 7f 04 84 c0 75 58 48 89 f0 48 89 f2 0f b6 6b RSP: 0018:ffffc90002f477c0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffc9000e822000 RDX: 0000000000000000 RSI: ffffffff8c43e580 RDI: 0000000000000000 RBP: ffffffff8c43d520 R08: 0000000000000001 R09: ffffed1004c45209 R10: ffff88802622904f R11: 0000000000000001 R12: ffff888032d3a000 R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000000 FS: 00007f20fbfaf6c0(0000) GS:ffff88812482c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000692000 CR3: 0000000059abe000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess): 0: df 41 54 filds 0x54(%rcx) 3: 55 push %rbp 4: 53 push %rbx 5: 48 89 fb mov %rdi,%rbx 8: 48 83 ec 08 sub $0x8,%rsp c: eb 08 jmp 0x16 e: 40 84 ed test %bpl,%bpl 11: 74 61 je 0x74 13: 4c 89 e6 mov %r12,%rsi 16: 48 89 df mov %rbx,%rdi 19: 48 83 c3 01 add $0x1,%rbx 1d: 48 89 f8 mov %rdi,%rax 20: 48 89 fa mov %rdi,%rdx 23: 48 c1 e8 03 shr $0x3,%rax 27: 83 e2 07 and $0x7,%edx * 2a: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax <-- trapping instruction 2f: 38 d0 cmp %dl,%al 31: 7f 04 jg 0x37 33: 84 c0 test %al,%al 35: 75 58 jne 0x8f 37: 48 89 f0 mov %rsi,%rax 3a: 48 89 f2 mov %rsi,%rdx 3d: 0f .byte 0xf 3e: b6 6b mov $0x6b,%dh