Hello, syzbot found the following issue on: HEAD commit: 4e78c578 Add linux-next specific files for 20201030 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=110d0c92500000 kernel config: https://syzkaller.appspot.com/x/.config?x=83318758268dc331 dashboard link: https://syzkaller.appspot.com/bug?extid=3e565bbd2673747f90c2 compiler: gcc (GCC) 10.1.0-syz 20200507 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+3e565bbd2673747f90c2@xxxxxxxxxxxxxxxxxxxxxxxxx MINIX-fs: mounting unchecked file system, running fsck is recommended MINIX-fs: deleted inode referenced: 6 ================================================================== BUG: KASAN: use-after-free in path_init+0x14ba/0x17d0 fs/namei.c:2208 Read of size 8 at addr ffff8880633cc400 by task syz-executor.3/14486 CPU: 1 PID: 14486 Comm: syz-executor.3 Not tainted 5.10.0-rc1-next-20201030-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+0x107/0x163 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x4c8 mm/kasan/report.c:385 __kasan_report mm/kasan/report.c:545 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562 path_init+0x14ba/0x17d0 fs/namei.c:2208 path_parentat+0x22/0x1b0 fs/namei.c:2385 filename_parentat+0x188/0x560 fs/namei.c:2408 do_renameat2+0x16e/0xc00 fs/namei.c:4375 __do_sys_renameat fs/namei.c:4501 [inline] __se_sys_renameat fs/namei.c:4498 [inline] __x64_sys_renameat+0xbf/0xf0 fs/namei.c:4498 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45deb9 Code: 0d b4 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 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fbef8029c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000108 RAX: ffffffffffffffda RBX: 0000000000027340 RCX: 000000000045deb9 RDX: 0000000000000006 RSI: 0000000020000500 RDI: 0000000000000003 RBP: 000000000118bf68 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000200017c0 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007ffe203745cf R14: 00007fbef802a9c0 R15: 000000000118bf2c Allocated by task 14486: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:461 slab_post_alloc_hook mm/slab.h:506 [inline] slab_alloc_node mm/slub.c:2889 [inline] slab_alloc mm/slub.c:2897 [inline] kmem_cache_alloc+0x122/0x460 mm/slub.c:2902 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138 getname_flags+0x9a/0xe0 include/linux/audit.h:319 getname fs/namei.c:209 [inline] __do_sys_renameat fs/namei.c:4501 [inline] __se_sys_renameat fs/namei.c:4498 [inline] __x64_sys_renameat+0xad/0xf0 fs/namei.c:4498 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 14486: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0x102/0x140 mm/kasan/common.c:422 slab_free_hook mm/slub.c:1544 [inline] slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1577 slab_free mm/slub.c:3140 [inline] kmem_cache_free+0x82/0x350 mm/slub.c:3156 putname+0xe1/0x120 fs/namei.c:259 do_renameat2+0x3e6/0xc00 fs/namei.c:4481 __do_sys_renameat fs/namei.c:4501 [inline] __se_sys_renameat fs/namei.c:4498 [inline] __x64_sys_renameat+0xbf/0xf0 fs/namei.c:4498 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 ffff8880633cc400 which belongs to the cache names_cache of size 4096 The buggy address is located 0 bytes inside of 4096-byte region [ffff8880633cc400, ffff8880633cd400) The buggy address belongs to the page: page:00000000f2c066e0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x633c8 head:00000000f2c066e0 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff8880101c1280 raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880633cc300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880633cc380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880633cc400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880633cc480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880633cc500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This report is generated by a bot. 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