On Wed, Feb 7, 2018 at 4:31 AM, syzbot <syzbot+7330488a9c5c5cb5452e@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > Hello, > > syzbot hit the following crash on upstream commit > e237f98a9c134c3d600353f21e07db915516875b (Mon Feb 5 21:35:56 2018 +0000) > Merge tag 'xfs-4.16-merge-5' of > git://git.kernel.org/pub/scm/fs/xfs/xfs-linux > > C reproducer is attached. > syzkaller reproducer is attached. > Raw console output is attached. > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached. > user-space arch: i386 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+7330488a9c5c5cb5452e@xxxxxxxxxxxxxxxxxxxxxxxxx > 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. > > ------------[ cut here ]------------ > Bad or missing usercopy whitelist? Kernel memory exposure attempt detected > from SLAB object 'skbuff_head_cache' (offset 64, size 16)! > WARNING: CPU: 0 PID: 3994 at mm/usercopy.c:81 usercopy_warn+0xdb/0x100 > mm/usercopy.c:76 > Kernel panic - not syncing: panic_on_warn set ... > > CPU: 0 PID: 3994 Comm: syzkaller552561 Not tainted 4.15.0+ #210 > 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+0x194/0x257 lib/dump_stack.c:53 > panic+0x1e4/0x41c kernel/panic.c:183 > __warn+0x1dc/0x200 kernel/panic.c:547 > report_bug+0x211/0x2d0 lib/bug.c:184 > fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178 > fixup_bug arch/x86/kernel/traps.c:247 [inline] > do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296 > do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 > invalid_op+0x22/0x40 arch/x86/entry/entry_64.S:984 > RIP: 0010:usercopy_warn+0xdb/0x100 mm/usercopy.c:76 > RSP: 0018:ffff8801cf3873f0 EFLAGS: 00010286 > RAX: dffffc0000000008 RBX: ffffffff86801907 RCX: ffffffff815a585e > RDX: 0000000000000000 RSI: 1ffff10039e70e2e RDI: 1ffff10039e70e03 > RBP: ffff8801cf387448 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000866 R11: 0000000000000000 R12: ffffffff86403180 > R13: ffffffff85f2d4c0 R14: 0000000000000040 R15: 0000000000000010 > __check_heap_object+0x89/0xc0 mm/slab.c:4426 > check_heap_object mm/usercopy.c:236 [inline] > __check_object_size+0x272/0x530 mm/usercopy.c:259 > check_object_size include/linux/thread_info.h:112 [inline] > check_copy_size include/linux/thread_info.h:143 [inline] > copy_to_user include/linux/uaccess.h:154 [inline] > put_cmsg_compat+0x724/0xa50 net/compat.c:254 > put_cmsg+0x33a/0x3f0 net/core/scm.c:225 > sock_recv_errqueue+0x200/0x3e0 net/core/sock.c:2910 > packet_recvmsg+0xb2e/0x17a0 net/packet/af_packet.c:3296 > sock_recvmsg_nosec net/socket.c:803 [inline] > sock_recvmsg+0xc9/0x110 net/socket.c:810 > ___sys_recvmsg+0x2a4/0x640 net/socket.c:2205 > __sys_recvmsg+0xe2/0x210 net/socket.c:2250 > C_SYSC_recvmsg net/compat.c:751 [inline] > compat_SyS_recvmsg+0x2a/0x40 net/compat.c:749 > do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] > do_fast_syscall_32+0x3ee/0xfa1 arch/x86/entry/common.c:392 > entry_SYSENTER_compat+0x54/0x63 arch/x86/entry/entry_64_compat.S:129 > RIP: 0023:0xf7f45c79 > RSP: 002b:00000000fffebddc EFLAGS: 00000217 ORIG_RAX: 0000000000000174 > RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000020006fc8 > RDX: 0000000000002000 RSI: 0000000000000004 RDI: 0000000000000004 > RBP: 0000000020000fe6 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > Dumping ftrace buffer: > (ftrace buffer empty) > Kernel Offset: disabled > Rebooting in 86400 seconds.. > > > --- > This bug is generated by a dumb bot. It may contain errors. > See https://goo.gl/tpsmEJ for details. > Direct all questions to syzkaller@xxxxxxxxxxxxxxxx. > > 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. #syz dup: WARNING in usercopy_warn Same root cause and will have the same fix. -Kees -- Kees Cook Pixel Security -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
