Messages in this thread | | | Date | Sun, 26 Apr 2020 01:58:10 -0700 | Subject | KASAN: use-after-free Read in get_block | From | syzbot <> |
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Hello,
syzbot found the following crash on:
HEAD commit: 189522da Merge tag 'for_linus' of git://git.kernel.org/pub.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=14193487e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=b7a70e992f2f9b68 dashboard link: https://syzkaller.appspot.com/bug?extid=3b7b03a0c28948054fb5 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16cb136fe00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12fd5930100000
Bisection is inconclusive: the bug happens on the oldest tested release.
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=122603f0100000 final crash: https://syzkaller.appspot.com/x/report.txt?x=112603f0100000 console output: https://syzkaller.appspot.com/x/log.txt?x=162603f0100000
IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+3b7b03a0c28948054fb5@syzkaller.appspotmail.com
================================================================== BUG: KASAN: use-after-free in add_chain fs/minix/itree_common.c:14 [inline] BUG: KASAN: use-after-free in get_branch fs/minix/itree_common.c:52 [inline] BUG: KASAN: use-after-free in get_block+0x110f/0x1380 fs/minix/itree_common.c:160 Read of size 2 at addr ffff888082c493be by task syz-executor205/7041
CPU: 1 PID: 7041 Comm: syz-executor205 Not tainted 5.7.0-rc2-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+0x188/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:382 __kasan_report.cold+0x35/0x4d mm/kasan/report.c:511 kasan_report+0x33/0x50 mm/kasan/common.c:625 add_chain fs/minix/itree_common.c:14 [inline] get_branch fs/minix/itree_common.c:52 [inline] get_block+0x110f/0x1380 fs/minix/itree_common.c:160 minix_get_block+0xe5/0x110 fs/minix/inode.c:376 block_read_full_page+0x2bf/0x1010 fs/buffer.c:2290 do_read_cache_page+0x1053/0x1810 mm/filemap.c:2768 read_mapping_page include/linux/pagemap.h:397 [inline] dir_get_page.isra.0+0x1d/0x60 fs/minix/dir.c:70 minix_find_entry+0x200/0x7b0 fs/minix/dir.c:170 minix_inode_by_name+0x6d/0x452 fs/minix/dir.c:454 minix_lookup fs/minix/namei.c:30 [inline] minix_lookup+0x103/0x190 fs/minix/namei.c:22 lookup_open+0x8d7/0x1320 fs/namei.c:3060 open_last_lookups fs/namei.c:3155 [inline] path_openat+0x93f/0x27d0 fs/namei.c:3343 do_filp_open+0x192/0x260 fs/namei.c:3373 do_sys_openat2+0x585/0x7d0 fs/open.c:1148 do_sys_open+0xc3/0x140 fs/open.c:1164 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x445ef9 Code: ed cb 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 bb cb fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffc4f7dec58 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000445ef9 RDX: 0000000000000000 RSI: 0000000000020040 RDI: 0000000020000040 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000402fd0 R10: 00007ffc4f7deb30 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000402fd0 R14: 0000000000000000 R15: 0000000000000000
The buggy address belongs to the page: page:ffffea00020b1240 refcount:2 mapcount:0 mapping:000000007b3de2b2 index:0x2f24f minix_aops name:"/" flags: 0xfffe0000002016(referenced|uptodate|lru|private) raw: 00fffe0000002016 ffffea0002389288 ffffea00020b1388 ffff8880846492e8 raw: 000000000002f24f ffff8880856d0ae0 00000002ffffffff ffff8880a9550000 page dumped because: kasan: bad access detected page->mem_cgroup:ffff8880a9550000
Memory state around the buggy address: ffff888082c49280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888082c49300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888082c49380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffff888082c49400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888082c49480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================
--- This bug 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@googlegroups.com.
syzbot will keep track of this bug report. 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 bug, for details see: https://goo.gl/tpsmEJ#testing-patches
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