Hello, syzbot found the following issue on: HEAD commit: 5631c5e0 Merge tag 'xfs-5.9-merge-7' of git://git.kernel.o.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=17076984900000 kernel config: https://syzkaller.appspot.com/x/.config?x=afba7c06f91e56eb dashboard link: https://syzkaller.appspot.com/bug?extid=bbeb1c88016c7db4aa24 compiler: gcc (GCC) 10.1.0-syz 20200507 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1502ce02900000 The issue was bisected to: commit e24ab0ef689de43649327f54cd1088f3dad25bb3 Author: Christoph Hellwig <hch@xxxxxx> Date: Tue Jul 21 08:48:15 2020 +0000 fs: push the getname from do_rmdir into the callers bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=155f36c2900000 final oops: https://syzkaller.appspot.com/x/report.txt?x=175f36c2900000 console output: https://syzkaller.appspot.com/x/log.txt?x=135f36c2900000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+bbeb1c88016c7db4aa24@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: e24ab0ef689d ("fs: push the getname from do_rmdir into the callers") ================================================================== BUG: KASAN: use-after-free in path_init+0x116b/0x13c0 fs/namei.c:2207 Read of size 8 at addr ffff88807853c940 by task syz-executor.2/8233 CPU: 0 PID: 8233 Comm: syz-executor.2 Not tainted 5.8.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x436 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 path_init+0x116b/0x13c0 fs/namei.c:2207 path_parentat+0x22/0x1b0 fs/namei.c:2384 filename_parentat+0x188/0x560 fs/namei.c:2407 do_rmdir+0xa8/0x440 fs/namei.c:3732 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45ce79 Code: 2d b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f756fb2bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000054 RAX: ffffffffffffffda RBX: 00000000000260c0 RCX: 000000000045ce79 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200000c0 RBP: 000000000118bff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bfcc R13: 00007ffedeb9931f R14: 00007f756fb2c9c0 R15: 000000000118bfcc Allocated by task 8233: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494 slab_post_alloc_hook mm/slab.h:586 [inline] slab_alloc mm/slab.c:3320 [inline] kmem_cache_alloc+0x12c/0x3b0 mm/slab.c:3484 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138 getname_flags include/linux/audit.h:320 [inline] getname fs/namei.c:209 [inline] __do_sys_rmdir fs/namei.c:3783 [inline] __se_sys_rmdir fs/namei.c:3781 [inline] __x64_sys_rmdir+0xb1/0x100 fs/namei.c:3781 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 8233: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0xf5/0x140 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kmem_cache_free+0x7f/0x310 mm/slab.c:3694 putname+0xe1/0x120 fs/namei.c:259 do_rmdir+0x145/0x440 fs/namei.c:3773 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff88807853c940 which belongs to the cache names_cache of size 4096 The buggy address is located 0 bytes inside of 4096-byte region [ffff88807853c940, ffff88807853d940) The buggy address belongs to the page: page:ffffea0001e14f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 head:ffffea0001e14f00 order:1 compound_mapcount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea0001e14e88 ffffea0001e14f88 ffff8880aa246380 raw: 0000000000000000 ffff88807853c940 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88807853c800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807853c880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88807853c900: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff88807853c980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807853ca00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
