This is a note to let you know that I've just added the patch titled ipv4: fix buffer overflow in ip_options_compile() to the 3.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ipv4-fix-buffer-overflow-in-ip_options_compile.patch and it can be found in the queue-3.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Sat Jul 26 10:16:13 PDT 2014 From: Eric Dumazet <edumazet@xxxxxxxxxx> Date: Mon, 21 Jul 2014 07:17:42 +0200 Subject: ipv4: fix buffer overflow in ip_options_compile() From: Eric Dumazet <edumazet@xxxxxxxxxx> [ Upstream commit 10ec9472f05b45c94db3c854d22581a20b97db41 ] There is a benign buffer overflow in ip_options_compile spotted by AddressSanitizer[1] : Its benign because we always can access one extra byte in skb->head (because header is followed by struct skb_shared_info), and in this case this byte is not even used. [28504.910798] ================================================================== [28504.912046] AddressSanitizer: heap-buffer-overflow in ip_options_compile [28504.913170] Read of size 1 by thread T15843: [28504.914026] [<ffffffff81802f91>] ip_options_compile+0x121/0x9c0 [28504.915394] [<ffffffff81804a0d>] ip_options_get_from_user+0xad/0x120 [28504.916843] [<ffffffff8180dedf>] do_ip_setsockopt.isra.15+0x8df/0x1630 [28504.918175] [<ffffffff8180ec60>] ip_setsockopt+0x30/0xa0 [28504.919490] [<ffffffff8181e59b>] tcp_setsockopt+0x5b/0x90 [28504.920835] [<ffffffff8177462f>] sock_common_setsockopt+0x5f/0x70 [28504.922208] [<ffffffff817729c2>] SyS_setsockopt+0xa2/0x140 [28504.923459] [<ffffffff818cfb69>] system_call_fastpath+0x16/0x1b [28504.924722] [28504.925106] Allocated by thread T15843: [28504.925815] [<ffffffff81804995>] ip_options_get_from_user+0x35/0x120 [28504.926884] [<ffffffff8180dedf>] do_ip_setsockopt.isra.15+0x8df/0x1630 [28504.927975] [<ffffffff8180ec60>] ip_setsockopt+0x30/0xa0 [28504.929175] [<ffffffff8181e59b>] tcp_setsockopt+0x5b/0x90 [28504.930400] [<ffffffff8177462f>] sock_common_setsockopt+0x5f/0x70 [28504.931677] [<ffffffff817729c2>] SyS_setsockopt+0xa2/0x140 [28504.932851] [<ffffffff818cfb69>] system_call_fastpath+0x16/0x1b [28504.934018] [28504.934377] The buggy address ffff880026382828 is located 0 bytes to the right [28504.934377] of 40-byte region [ffff880026382800, ffff880026382828) [28504.937144] [28504.937474] Memory state around the buggy address: [28504.938430] ffff880026382300: ........ rrrrrrrr rrrrrrrr rrrrrrrr [28504.939884] ffff880026382400: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr [28504.941294] ffff880026382500: .....rrr rrrrrrrr rrrrrrrr rrrrrrrr [28504.942504] ffff880026382600: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr [28504.943483] ffff880026382700: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr [28504.944511] >ffff880026382800: .....rrr rrrrrrrr rrrrrrrr rrrrrrrr [28504.945573] ^ [28504.946277] ffff880026382900: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr [28505.094949] ffff880026382a00: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr [28505.096114] ffff880026382b00: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr [28505.097116] ffff880026382c00: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr [28505.098472] ffff880026382d00: ffffffff rrrrrrrr rrrrrrrr rrrrrrrr [28505.099804] Legend: [28505.100269] f - 8 freed bytes [28505.100884] r - 8 redzone bytes [28505.101649] . - 8 allocated bytes [28505.102406] x=1..7 - x allocated bytes + (8-x) redzone bytes [28505.103637] ================================================================== [1] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv4/ip_options.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/net/ipv4/ip_options.c +++ b/net/ipv4/ip_options.c @@ -288,6 +288,10 @@ int ip_options_compile(struct net *net, optptr++; continue; } + if (unlikely(l < 2)) { + pp_ptr = optptr; + goto error; + } optlen = optptr[1]; if (optlen < 2 || optlen > l) { pp_ptr = optptr; Patches currently in stable-queue which might be from edumazet@xxxxxxxxxx are queue-3.15/appletalk-fix-socket-referencing-in-skb.patch queue-3.15/vlan-free-percpu-stats-in-device-destructor.patch queue-3.15/8021q-fix-a-potential-memory-leak.patch queue-3.15/ipv4-fix-dst-race-in-sk_dst_get.patch queue-3.15/tcp-fix-tcp_match_skb_to_sack-for-unaligned-sack-at-end-of-an-skb.patch queue-3.15/ipv4-irq-safe-sk_dst_set-and-ipv4_sk_update_pmtu-fix.patch queue-3.15/net-fix-sparse-warning-in-sk_dst_set.patch queue-3.15/bnx2x-fix-possible-panic-under-memory-stress.patch queue-3.15/ipv4-fix-buffer-overflow-in-ip_options_compile.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html