RBP: 00007f018e6b21d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffd35f305bf R14: 00007f018e6b2300 R15: 0000000000022000 general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 PID: 34986 Comm: syz-executor.6 Not tainted 6.3.0-rc6-next-20230413 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:folio_wait_stable+0x23/0xe0 Code: 90 90 90 90 90 90 90 f3 0f 1e fa 55 48 89 fd 53 e8 62 58 e7 ff 48 8d 7d 18 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 a4 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b RSP: 0018:ffff888016a579f0 EFLAGS: 00010213 RAX: dffffc0000000000 RBX: ffff88801bff4808 RCX: ffffc90004e06000 RDX: 0000000000000001 RSI: ffffffff81646e3e RDI: 000000000000000c RBP: fffffffffffffff4 R08: 0000000000000001 R09: ffffffff856c1213 R10: fffffbfff0ad8242 R11: 0000000000000001 R12: 0000000000000000 R13: ffff88801bff4a30 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f018e6b2700(0000) GS:ffff88806ce00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f018e6b1f78 CR3: 0000000048220000 CR4: 0000000000350ef0 Call Trace: ext4_da_write_begin+0x38d/0x830 generic_perform_write+0x25a/0x580 ext4_buffered_write_iter+0x164/0x460 ext4_file_write_iter+0x3ff/0x1950 vfs_write+0x9b5/0xdc0 ksys_write+0x12b/0x260 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc RIP: 0033:0x7f019113cb19 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f018e6b2188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f019124ff60 RCX: 00007f019113cb19 RDX: 00000000000292e9 RSI: 0000000020000080 RDI: 0000000000000006 RBP: 00007f018e6b21d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffd35f305bf R14: 00007f018e6b2300 R15: 0000000000022000 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:folio_wait_stable+0x23/0xe0 Code: 90 90 90 90 90 90 90 f3 0f 1e fa 55 48 89 fd 53 e8 62 58 e7 ff 48 8d 7d 18 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 a4 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b RSP: 0018:ffff888016a579f0 EFLAGS: 00010213 RAX: dffffc0000000000 RBX: ffff88801bff4808 RCX: ffffc90004e06000 RDX: 0000000000000001 RSI: ffffffff81646e3e RDI: 000000000000000c RBP: fffffffffffffff4 R08: 0000000000000001 R09: ffffffff856c1213 R10: fffffbfff0ad8242 R11: 0000000000000001 R12: 0000000000000000 R13: ffff88801bff4a30 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f018e6b2700(0000) GS:ffff88806ce00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f018e6b1f78 CR3: 0000000048220000 CR4: 0000000000350ef0 ================================================================== BUG: KASAN: slab-use-after-free in rwsem_down_write_slowpath+0x13a6/0x14a0 Read of size 4 at addr ffff8880490fb5b4 by task syz-executor.6/268 CPU: 0 PID: 268 Comm: syz-executor.6 Tainted: G D 6.3.0-rc6-next-20230413 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack_lvl+0x91/0xf0 print_report+0xcc/0x620 kasan_report+0xc0/0xf0 rwsem_down_write_slowpath+0x13a6/0x14a0 down_write+0x1c3/0x1f0 vfs_unlink+0xd9/0x930 do_unlinkat+0x3b9/0x650 __x64_sys_unlink+0xca/0x110 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc RIP: 0033:0x7f019113c457 Code: 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd35f2f708 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f019113c457 RDX: 00007ffd35f2f740 RSI: 00007ffd35f2f740 RDI: 00007ffd35f2f7d0 RBP: 00007ffd35f2f7d0 R08: 0000000000000001 R09: 00007ffd35f2f5a0 R10: 000055555651bd13 R11: 0000000000000206 R12: 00007f0191196105 R13: 00007ffd35f30890 R14: 000055555651bc20 R15: 00007ffd35f308d0 Allocated by task 34977: kasan_save_stack+0x22/0x50 kasan_set_track+0x25/0x30 __kasan_slab_alloc+0x59/0x70 kmem_cache_alloc_node+0x189/0x3a0 copy_process+0x3c2/0x7330 kernel_clone+0xeb/0x7d0 __do_sys_clone+0xba/0x100 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc Freed by task 34977: kasan_save_stack+0x22/0x50 kasan_set_track+0x25/0x30 kasan_save_free_info+0x2e/0x50 __kasan_slab_free+0x10a/0x190 kmem_cache_free+0xff/0x4a0 _free_event+0xab4/0x1150 perf_event_release_kernel+0x5b8/0x7a0 perf_release+0x37/0x50 __fput+0x263/0xa40 task_work_run+0x174/0x280 exit_to_user_mode_prepare+0x17d/0x180 syscall_exit_to_user_mode+0x1d/0x50 do_syscall_64+0x4c/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc Last potentially related work creation: kasan_save_stack+0x22/0x50 __kasan_record_aux_stack+0x95/0xb0 __call_rcu_common.constprop.0+0x6a/0xb90 put_task_struct_rcu_user+0x87/0xd0 __schedule+0x995/0x2a00 __cond_resched+0x46/0x70 __inode_security_revalidate+0x119/0x140 selinux_inode_permission+0x274/0x5e0 security_inode_permission+0x9c/0x100 inode_permission.part.0+0x125/0x520 link_path_walk.part.0+0x85e/0xd90 path_lookupat+0xb7/0x850 filename_lookup+0x1d2/0x590 user_path_at_empty+0x46/0x70 do_faccessat+0x127/0xae0 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc The buggy address belongs to the object at ffff8880490fb580 which belongs to the cache task_struct of size 6592 The buggy address is located 52 bytes inside of freed 6592-byte region [ffff8880490fb580, ffff8880490fcf40) The buggy address belongs to the physical page: page:0000000032e21309 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x490f8 head:0000000032e21309 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88800e08c801 flags: 0x100000000010200(slab|head|node=0|zone=1) page_type: 0xffffffff() raw: 0100000000010200 ffff888008792640 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000040004 00000001ffffffff ffff88800e08c801 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880490fb480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880490fb500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880490fb580: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880490fb600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880490fb680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 90 nop 1: 90 nop 2: 90 nop 3: 90 nop 4: 90 nop 5: 90 nop 6: 90 nop 7: f3 0f 1e fa endbr64 b: 55 push %rbp c: 48 89 fd mov %rdi,%rbp f: 53 push %rbx 10: e8 62 58 e7 ff callq 0xffe75877 15: 48 8d 7d 18 lea 0x18(%rbp),%rdi 19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 20: fc ff df 23: 48 89 fa mov %rdi,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2e: 0f 85 a4 00 00 00 jne 0xd8 34: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 3b: fc ff df 3e: 48 rex.W 3f: 8b .byte 0x8b