Messages in this thread |  | | Date | Mon, 02 Apr 2018 10:01:02 -0700 | Subject | KASAN: use-after-free Write in __ext4_expand_extra_isize | From | syzbot <> |
| |
Hello,
syzbot hit the following crash on upstream commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda (Sun Apr 1 21:20:27 2018 +0000) Linux 4.16 syzbot dashboard link: https://syzkaller.appspot.com/bug?extid=f584efa0ac7213c226b7
C reproducer: https://syzkaller.appspot.com/x/repro.c?id=6513385206185984 syzkaller reproducer: https://syzkaller.appspot.com/x/repro.syz?id=5304036769136640 Raw console output: https://syzkaller.appspot.com/x/log.txt?id=5041749693038592 Kernel config: https://syzkaller.appspot.com/x/.config?id=-2374466361298166459 compiler: gcc (GCC) 7.1.1 20170620
IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+f584efa0ac7213c226b7@syzkaller.appspotmail.com It will help syzbot understand when the bug is fixed. See footer for details. If you forward the report, please keep this part and the footer.
IPVS: ftp: loaded support on port[0] = 21 EXT4-fs (sda1): re-mounted. Opts: debug_want_extra_isize=7632 ================================================================== BUG: KASAN: use-after-free in memset include/linux/string.h:330 [inline] BUG: KASAN: use-after-free in __ext4_expand_extra_isize+0x157/0x230 fs/ext4/inode.c:5779 Write of size 7600 at addr ffff8801c7ee86a0 by task syzkaller547255/4428
CPU: 0 PID: 4428 Comm: syzkaller547255 Not tainted 4.16.0+ #10 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report+0x23c/0x360 mm/kasan/report.c:412 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x137/0x190 mm/kasan/kasan.c:267 memset+0x23/0x40 mm/kasan/kasan.c:285 memset include/linux/string.h:330 [inline] __ext4_expand_extra_isize+0x157/0x230 fs/ext4/inode.c:5779 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5831 [inline] ext4_mark_inode_dirty+0x7a9/0xa10 fs/ext4/inode.c:5907 ext4_unlink+0xc6f/0x1100 fs/ext4/namei.c:3038 vfs_unlink+0x283/0x480 fs/namei.c:3978 do_unlinkat+0x731/0x940 fs/namei.c:4041 SYSC_unlink fs/namei.c:4088 [inline] SyS_unlink+0x26/0x30 fs/namei.c:4086 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x447b77 RSP: 002b:00007ffc704d9d88 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000447b77 RDX: 00007ffc704d9d90 RSI: 00007ffc704d9d90 RDI: 00007ffc704d9e20 RBP: 00007ffc704db5a0 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000006 R11: 0000000000000206 R12: 0000000001c648a0 R13: 0000000000000000 R14: 0000000000007384 R15: 00007ffc704daf98
The buggy address belongs to the page: page:ffffea00071fba00 count:2 mapcount:0 mapping:ffff8801d52ef660 index:0x4a7 flags: 0x2fffc0000001064(referenced|lru|active|private) raw: 02fffc0000001064 ffff8801d52ef660 00000000000004a7 00000002ffffffff raw: ffffea0006e70c20 ffffea0006d9a5a0 ffff8801a99933f0 ffff8801d9a96b40 page dumped because: kasan: bad access detected page->mem_cgroup:ffff8801d9a96b40
Memory state around the buggy address: ffff8801c7ee9f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8801c7ee9f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > ffff8801c7eea000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8801c7eea080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8801c7eea100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================
--- This bug is generated by a dumb bot. It may contain errors. See https://goo.gl/tpsmEJ for details. Direct all questions to syzkaller@googlegroups.com.
syzbot will keep track of this bug report. If you forgot to add the Reported-by tag, once the fix for this bug is merged into any tree, please reply to this email with: #syz fix: exact-commit-title If you want to test a patch for this bug, please reply with: #syz test: git://repo/address.git branch and provide the patch inline or as an attachment. To mark this as a duplicate of another syzbot report, please reply with: #syz dup: exact-subject-of-another-report If it's a one-off invalid bug report, please reply with: #syz invalid Note: if the crash happens again, it will cause creation of a new bug report. Note: all commands must start from beginning of the line in the email body.
|  |