BUG: kernel NULL pointer dereference, address: 0000000000000034 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 800000010f582067 P4D 800000010f582067 PUD 0 Oops: Oops: 0000 [#1] SMP KASAN PTI CPU: 1 UID: 0 PID: 6005 Comm: syz.2.21 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:kmem_cache_alloc_noprof+0x2e/0x6e0 mm/slub.c:5252 Code: 55 41 57 41 56 41 55 41 54 53 48 83 ec 38 89 f5 49 89 fe 65 48 8b 05 c1 43 ab 10 48 89 44 24 30 48 8b 44 24 68 48 89 44 24 18 <8b> 47 34 48 89 44 24 08 8b 1d 44 78 ab 0d 21 f3 89 df e8 db 9c fd RSP: 0018:ffffc90002dee640 EFLAGS: 00010282 RAX: ffffffff822e7088 RBX: 0000000000012800 RCX: ffff888105ee3a00 RDX: 0000000000000000 RSI: 0000000000012800 RDI: 0000000000000000 RBP: 0000000000012800 R08: ffff888105ee3a00 R09: 0000000000000002 R10: 00000000fffffff0 R11: 0000000000000000 R12: ffff88801d2b1aa0 R13: 1ffff11003a56454 R14: 0000000000000000 R15: 0000000000000020 FS: 00007f819a1c56c0(0000) GS:ffff8881a39dd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000034 CR3: 000000010e704000 CR4: 00000000000006f0 Call Trace: cache_alloc_handle mm/zsmalloc.c:410 [inline] zs_malloc+0x88/0x720 mm/zsmalloc.c:1281 zswap_compress mm/zswap.c:910 [inline] zswap_store_page mm/zswap.c:1429 [inline] zswap_store+0x1062/0x1f40 mm/zswap.c:1540 swap_writeout+0x710/0xd70 mm/page_io.c:275 writeout mm/vmscan.c:662 [inline] pageout mm/vmscan.c:721 [inline] shrink_folio_list+0x3011/0x4c70 mm/vmscan.c:1453 reclaim_folio_list+0xeb/0x500 mm/vmscan.c:2233 reclaim_pages+0x454/0x520 mm/vmscan.c:2270 madvise_cold_or_pageout_pte_range+0x1974/0x1d00 mm/madvise.c:565 walk_pmd_range mm/pagewalk.c:130 [inline] walk_pud_range mm/pagewalk.c:224 [inline] walk_p4d_range mm/pagewalk.c:262 [inline] walk_pgd_range+0xfe9/0x1d40 mm/pagewalk.c:303 __walk_page_range+0x14c/0x710 mm/pagewalk.c:410 walk_page_range_vma+0x393/0x440 mm/pagewalk.c:705 madvise_pageout_page_range mm/madvise.c:624 [inline] madvise_pageout mm/madvise.c:649 [inline] madvise_vma_behavior+0x311f/0x3a10 mm/madvise.c:1352 madvise_walk_vmas+0x51c/0xa30 mm/madvise.c:1669 madvise_do_behavior+0x38e/0x550 mm/madvise.c:1885 do_madvise+0x1bc/0x270 mm/madvise.c:1978 __do_sys_madvise mm/madvise.c:1987 [inline] __se_sys_madvise mm/madvise.c:1985 [inline] __x64_sys_madvise+0xa7/0xc0 mm/madvise.c:1985 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f819938ec29 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:00007f819a1c5038 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 00007f81995d5fa0 RCX: 00007f819938ec29 RDX: 0000000000000015 RSI: 0000000000600003 RDI: 0000200000000000 RBP: 00007f8199411e41 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f81995d6038 R14: 00007f81995d5fa0 R15: 00007ffe68a453c8 Modules linked in: CR2: 0000000000000034 ---[ end trace 0000000000000000 ]--- RIP: 0010:kmem_cache_alloc_noprof+0x2e/0x6e0 mm/slub.c:5252 Code: 55 41 57 41 56 41 55 41 54 53 48 83 ec 38 89 f5 49 89 fe 65 48 8b 05 c1 43 ab 10 48 89 44 24 30 48 8b 44 24 68 48 89 44 24 18 <8b> 47 34 48 89 44 24 08 8b 1d 44 78 ab 0d 21 f3 89 df e8 db 9c fd RSP: 0018:ffffc90002dee640 EFLAGS: 00010282 RAX: ffffffff822e7088 RBX: 0000000000012800 RCX: ffff888105ee3a00 RDX: 0000000000000000 RSI: 0000000000012800 RDI: 0000000000000000 RBP: 0000000000012800 R08: ffff888105ee3a00 R09: 0000000000000002 R10: 00000000fffffff0 R11: 0000000000000000 R12: ffff88801d2b1aa0 R13: 1ffff11003a56454 R14: 0000000000000000 R15: 0000000000000020 FS: 00007f819a1c56c0(0000) GS:ffff8881a39dd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000034 CR3: 000000010e704000 CR4: 00000000000006f0 ---------------- Code disassembly (best guess): 0: 55 push %rbp 1: 41 57 push %r15 3: 41 56 push %r14 5: 41 55 push %r13 7: 41 54 push %r12 9: 53 push %rbx a: 48 83 ec 38 sub $0x38,%rsp e: 89 f5 mov %esi,%ebp 10: 49 89 fe mov %rdi,%r14 13: 65 48 8b 05 c1 43 ab mov %gs:0x10ab43c1(%rip),%rax # 0x10ab43dc 1a: 10 1b: 48 89 44 24 30 mov %rax,0x30(%rsp) 20: 48 8b 44 24 68 mov 0x68(%rsp),%rax 25: 48 89 44 24 18 mov %rax,0x18(%rsp) * 2a: 8b 47 34 mov 0x34(%rdi),%eax <-- trapping instruction 2d: 48 89 44 24 08 mov %rax,0x8(%rsp) 32: 8b 1d 44 78 ab 0d mov 0xdab7844(%rip),%ebx # 0xdab787c 38: 21 f3 and %esi,%ebx 3a: 89 df mov %ebx,%edi 3c: e8 .byte 0xe8 3d: db .byte 0xdb 3e: 9c pushf 3f: fd std