Zero length message leads to an empty skb loop0: detected capacity change from 0 to 32768 ======================================================= WARNING: The mand mount option has been deprecated and and is ignored by this kernel. Remove the mand option from the mount to silence this warning. ======================================================= xfs: Unknown parameter 'À' Oops: general protection fault, probably for non-canonical address 0xdffffc00000009c0: 0000 [#1] SMP KASAN NOPTI KASAN: probably user-memory-access in range [0x0000000000004e00-0x0000000000004e07] CPU: 0 UID: 0 PID: 5343 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:mem_cgroup_lruvec include/linux/memcontrol.h:720 [inline] RIP: 0010:lru_gen_test_recent mm/workingset.c:275 [inline] RIP: 0010:lru_gen_refault mm/workingset.c:296 [inline] RIP: 0010:workingset_refault+0x3f8/0x1170 mm/workingset.c:546 Code: 74 0c 48 c7 c7 e0 6a a2 8f e8 04 05 1d 00 4c 8b 35 3d c7 95 0d 49 81 c6 78 0c 00 00 4d 8d bd 00 4e 00 00 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 ce 05 00 00 49 63 07 4d 8d 34 c6 4c 89 RSP: 0018:ffffc9000a7b7880 EFLAGS: 00010206 RAX: 00000000000009c0 RBX: 0000000000000383 RCX: 0000000000100000 RDX: ffffc900208d2000 RSI: 0000000000000472 RDI: 0000000000000473 RBP: ffffc9000a7b7998 R08: ffff88801f7524c0 R09: 0000000000000002 R10: 0000000000000406 R11: 0000000000000002 R12: dffffc0000000000 R13: 0000000000000000 R14: ffff88801baf8c78 R15: 0000000000004e00 FS: 00007fbc75e8f6c0(0000) GS:ffff88808d22a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000040 CR3: 000000001234e000 CR4: 0000000000352ef0 Call Trace: filemap_add_folio+0x33f/0x540 mm/filemap.c:981 do_read_cache_folio+0x32e/0x590 mm/filemap.c:4063 freader_get_folio+0x3c7/0x830 lib/buildid.c:58 freader_fetch+0xa3/0x750 lib/buildid.c:101 __build_id_parse+0x133/0x7d0 lib/buildid.c:289 do_procmap_query fs/proc/task_mmu.c:733 [inline] procfs_procmap_ioctl+0x76f/0xce0 fs/proc/task_mmu.c:813 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbc74f8f7c9 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:00007fbc75e8f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fbc751e5fa0 RCX: 00007fbc74f8f7c9 RDX: 0000200000000180 RSI: 00000000c0686611 RDI: 000000000000000d RBP: 00007fbc75013f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbc751e6038 R14: 00007fbc751e5fa0 R15: 00007fff29f355e8 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:mem_cgroup_lruvec include/linux/memcontrol.h:720 [inline] RIP: 0010:lru_gen_test_recent mm/workingset.c:275 [inline] RIP: 0010:lru_gen_refault mm/workingset.c:296 [inline] RIP: 0010:workingset_refault+0x3f8/0x1170 mm/workingset.c:546 Code: 74 0c 48 c7 c7 e0 6a a2 8f e8 04 05 1d 00 4c 8b 35 3d c7 95 0d 49 81 c6 78 0c 00 00 4d 8d bd 00 4e 00 00 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 ce 05 00 00 49 63 07 4d 8d 34 c6 4c 89 RSP: 0018:ffffc9000a7b7880 EFLAGS: 00010206 RAX: 00000000000009c0 RBX: 0000000000000383 RCX: 0000000000100000 RDX: ffffc900208d2000 RSI: 0000000000000472 RDI: 0000000000000473 RBP: ffffc9000a7b7998 R08: ffff88801f7524c0 R09: 0000000000000002 R10: 0000000000000406 R11: 0000000000000002 R12: dffffc0000000000 R13: 0000000000000000 R14: ffff88801baf8c78 R15: 0000000000004e00 FS: 00007fbc75e8f6c0(0000) GS:ffff88808d22a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9f4cc08120 CR3: 000000001234e000 CR4: 0000000000352ef0 ---------------- Code disassembly (best guess): 0: 74 0c je 0xe 2: 48 c7 c7 e0 6a a2 8f mov $0xffffffff8fa26ae0,%rdi 9: e8 04 05 1d 00 call 0x1d0512 e: 4c 8b 35 3d c7 95 0d mov 0xd95c73d(%rip),%r14 # 0xd95c752 15: 49 81 c6 78 0c 00 00 add $0xc78,%r14 1c: 4d 8d bd 00 4e 00 00 lea 0x4e00(%r13),%r15 23: 4c 89 f8 mov %r15,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 0f b6 04 20 movzbl (%rax,%r12,1),%eax <-- trapping instruction 2f: 84 c0 test %al,%al 31: 0f 85 ce 05 00 00 jne 0x605 37: 49 63 07 movslq (%r15),%rax 3a: 4d 8d 34 c6 lea (%r14,%rax,8),%r14 3e: 4c rex.WR 3f: 89 .byte 0x89