mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-04-29 02:19:54 -04:00
5bfd37b4de
syszkaller reported use-after-free in tipc [1] When msg->rep skb is freed, set the pointer to NULL, so that caller does not free it again. [1] ================================================================== BUG: KASAN: use-after-free in skb_push+0xd4/0xe0 net/core/skbuff.c:1466 Read of size 8 at addr ffff8801c6e71e90 by task syz-executor5/4115 CPU: 1 PID: 4115 Comm: syz-executor5 Not tainted 4.13.0-rc4+ #32 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x24e/0x340 mm/kasan/report.c:409 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430 skb_push+0xd4/0xe0 net/core/skbuff.c:1466 tipc_nl_compat_recv+0x833/0x18f0 net/tipc/netlink_compat.c:1209 genl_family_rcv_msg+0x7b7/0xfb0 net/netlink/genetlink.c:598 genl_rcv_msg+0xb2/0x140 net/netlink/genetlink.c:623 netlink_rcv_skb+0x216/0x440 net/netlink/af_netlink.c:2397 genl_rcv+0x28/0x40 net/netlink/genetlink.c:634 netlink_unicast_kernel net/netlink/af_netlink.c:1265 [inline] netlink_unicast+0x4e8/0x6f0 net/netlink/af_netlink.c:1291 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1854 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 sock_write_iter+0x31a/0x5d0 net/socket.c:898 call_write_iter include/linux/fs.h:1743 [inline] new_sync_write fs/read_write.c:457 [inline] __vfs_write+0x684/0x970 fs/read_write.c:470 vfs_write+0x189/0x510 fs/read_write.c:518 SYSC_write fs/read_write.c:565 [inline] SyS_write+0xef/0x220 fs/read_write.c:557 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x4512e9 RSP: 002b:00007f3bc8184c08 EFLAGS: 00000216 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 00000000004512e9 RDX: 0000000000000020 RSI: 0000000020fdb000 RDI: 0000000000000006 RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000216 R12: 00000000004b5e76 R13: 00007f3bc8184b48 R14: 00000000004b5e86 R15: 0000000000000000 Allocated by task 4115: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489 kmem_cache_alloc_node+0x13d/0x750 mm/slab.c:3651 __alloc_skb+0xf1/0x740 net/core/skbuff.c:219 alloc_skb include/linux/skbuff.h:903 [inline] tipc_tlv_alloc+0x26/0xb0 net/tipc/netlink_compat.c:148 tipc_nl_compat_dumpit+0xf2/0x3c0 net/tipc/netlink_compat.c:248 tipc_nl_compat_handle net/tipc/netlink_compat.c:1130 [inline] tipc_nl_compat_recv+0x756/0x18f0 net/tipc/netlink_compat.c:1199 genl_family_rcv_msg+0x7b7/0xfb0 net/netlink/genetlink.c:598 genl_rcv_msg+0xb2/0x140 net/netlink/genetlink.c:623 netlink_rcv_skb+0x216/0x440 net/netlink/af_netlink.c:2397 genl_rcv+0x28/0x40 net/netlink/genetlink.c:634 netlink_unicast_kernel net/netlink/af_netlink.c:1265 [inline] netlink_unicast+0x4e8/0x6f0 net/netlink/af_netlink.c:1291 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1854 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 sock_write_iter+0x31a/0x5d0 net/socket.c:898 call_write_iter include/linux/fs.h:1743 [inline] new_sync_write fs/read_write.c:457 [inline] __vfs_write+0x684/0x970 fs/read_write.c:470 vfs_write+0x189/0x510 fs/read_write.c:518 SYSC_write fs/read_write.c:565 [inline] SyS_write+0xef/0x220 fs/read_write.c:557 entry_SYSCALL_64_fastpath+0x1f/0xbe Freed by task 4115: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3503 [inline] kmem_cache_free+0x77/0x280 mm/slab.c:3763 kfree_skbmem+0x1a1/0x1d0 net/core/skbuff.c:622 __kfree_skb net/core/skbuff.c:682 [inline] kfree_skb+0x165/0x4c0 net/core/skbuff.c:699 tipc_nl_compat_dumpit+0x36a/0x3c0 net/tipc/netlink_compat.c:260 tipc_nl_compat_handle net/tipc/netlink_compat.c:1130 [inline] tipc_nl_compat_recv+0x756/0x18f0 net/tipc/netlink_compat.c:1199 genl_family_rcv_msg+0x7b7/0xfb0 net/netlink/genetlink.c:598 genl_rcv_msg+0xb2/0x140 net/netlink/genetlink.c:623 netlink_rcv_skb+0x216/0x440 net/netlink/af_netlink.c:2397 genl_rcv+0x28/0x40 net/netlink/genetlink.c:634 netlink_unicast_kernel net/netlink/af_netlink.c:1265 [inline] netlink_unicast+0x4e8/0x6f0 net/netlink/af_netlink.c:1291 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1854 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 sock_write_iter+0x31a/0x5d0 net/socket.c:898 call_write_iter include/linux/fs.h:1743 [inline] new_sync_write fs/read_write.c:457 [inline] __vfs_write+0x684/0x970 fs/read_write.c:470 vfs_write+0x189/0x510 fs/read_write.c:518 SYSC_write fs/read_write.c:565 [inline] SyS_write+0xef/0x220 fs/read_write.c:557 entry_SYSCALL_64_fastpath+0x1f/0xbe The buggy address belongs to the object at ffff8801c6e71dc0 which belongs to the cache skbuff_head_cache of size 224 The buggy address is located 208 bytes inside of 224-byte region [ffff8801c6e71dc0, ffff8801c6e71ea0) The buggy address belongs to the page: page:ffffea00071b9c40 count:1 mapcount:0 mapping:ffff8801c6e71000 index:0x0 flags: 0x200000000000100(slab) raw: 0200000000000100 ffff8801c6e71000 0000000000000000 000000010000000c raw: ffffea0007224a20 ffff8801d98caf48 ffff8801d9e79040 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c6e71d80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8801c6e71e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801c6e71e80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8801c6e71f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801c6e71f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Jon Maloy <jon.maloy@ericsson.com> Cc: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.