2cdb66cccf
[ Upstream commit 0a8dd9f67cd0da7dc284f48b032ce00db1a68791 ]
syzbot found the following leak in sctp_process_init
BUG: memory leak
unreferenced object 0xffff88810ef68400 (size 1024):
comm "syz-executor273", pid 7046, jiffies 4294945598 (age 28.770s)
hex dump (first 32 bytes):
1d de 28 8d de 0b 1b e3 b5 c2 f9 68 fd 1a 97 25 ..(........h...%
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000a02cebbd>] kmemleak_alloc_recursive include/linux/kmemleak.h:55
[inline]
[<00000000a02cebbd>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<00000000a02cebbd>] slab_alloc mm/slab.c:3326 [inline]
[<00000000a02cebbd>] __do_kmalloc mm/slab.c:3658 [inline]
[<00000000a02cebbd>] __kmalloc_track_caller+0x15d/0x2c0 mm/slab.c:3675
[<000000009e6245e6>] kmemdup+0x27/0x60 mm/util.c:119
[<00000000dfdc5d2d>] kmemdup include/linux/string.h:432 [inline]
[<00000000dfdc5d2d>] sctp_process_init+0xa7e/0xc20
net/sctp/sm_make_chunk.c:2437
[<00000000b58b62f8>] sctp_cmd_process_init net/sctp/sm_sideeffect.c:682
[inline]
[<00000000b58b62f8>] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1384
[inline]
[<00000000b58b62f8>] sctp_side_effects net/sctp/sm_sideeffect.c:1194
[inline]
[<00000000b58b62f8>] sctp_do_sm+0xbdc/0x1d60 net/sctp/sm_sideeffect.c:1165
[<0000000044e11f96>] sctp_assoc_bh_rcv+0x13c/0x200
net/sctp/associola.c:1074
[<00000000ec43804d>] sctp_inq_push+0x7f/0xb0 net/sctp/inqueue.c:95
[<00000000726aa954>] sctp_backlog_rcv+0x5e/0x2a0 net/sctp/input.c:354
[<00000000d9e249a8>] sk_backlog_rcv include/net/sock.h:950 [inline]
[<00000000d9e249a8>] __release_sock+0xab/0x110 net/core/sock.c:2418
[<00000000acae44fa>] release_sock+0x37/0xd0 net/core/sock.c:2934
[<00000000963cc9ae>] sctp_sendmsg+0x2c0/0x990 net/sctp/socket.c:2122
[<00000000a7fc7565>] inet_sendmsg+0x64/0x120 net/ipv4/af_inet.c:802
[<00000000b732cbd3>] sock_sendmsg_nosec net/socket.c:652 [inline]
[<00000000b732cbd3>] sock_sendmsg+0x54/0x70 net/socket.c:671
[<00000000274c57ab>] ___sys_sendmsg+0x393/0x3c0 net/socket.c:2292
[<000000008252aedb>] __sys_sendmsg+0x80/0xf0 net/socket.c:2330
[<00000000f7bf23d1>] __do_sys_sendmsg net/socket.c:2339 [inline]
[<00000000f7bf23d1>] __se_sys_sendmsg net/socket.c:2337 [inline]
[<00000000f7bf23d1>] __x64_sys_sendmsg+0x23/0x30 net/socket.c:2337
[<00000000a8b4131f>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:3
The problem was that the peer.cookie value points to an skb allocated
area on the first pass through this function, at which point it is
overwritten with a heap allocated value, but in certain cases, where a
COOKIE_ECHO chunk is included in the packet, a second pass through
sctp_process_init is made, where the cookie value is re-allocated,
leaking the first allocation.
Fix is to always allocate the cookie value, and free it when we are done
using it.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reported-by: syzbot+f7e9153b037eac9b1df8@syzkaller.appspotmail.com
CC: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: netdev@vger.kernel.org
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.