Eric Dumazet 083b78a9ed ip: fix ip_mc_may_pull() return value
ip_mc_may_pull() must return 0 if there is a problem, not an errno.

syzbot reported :

BUG: KASAN: use-after-free in br_ip4_multicast_igmp3_report net/bridge/br_multicast.c:947 [inline]
BUG: KASAN: use-after-free in br_multicast_ipv4_rcv net/bridge/br_multicast.c:1631 [inline]
BUG: KASAN: use-after-free in br_multicast_rcv+0x3cd8/0x4440 net/bridge/br_multicast.c:1741
Read of size 4 at addr ffff88820a4084ee by task syz-executor.2/11183

CPU: 1 PID: 11183 Comm: syz-executor.2 Not tainted 5.0.0+ #14
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:131
 br_ip4_multicast_igmp3_report net/bridge/br_multicast.c:947 [inline]
 br_multicast_ipv4_rcv net/bridge/br_multicast.c:1631 [inline]
 br_multicast_rcv+0x3cd8/0x4440 net/bridge/br_multicast.c:1741
 br_handle_frame_finish+0xa3a/0x14c0 net/bridge/br_input.c:108
 br_nf_hook_thresh+0x2ec/0x380 net/bridge/br_netfilter_hooks.c:1005
 br_nf_pre_routing_finish+0x8e2/0x1750 net/bridge/br_netfilter_hooks.c:410
 NF_HOOK include/linux/netfilter.h:289 [inline]
 NF_HOOK include/linux/netfilter.h:283 [inline]
 br_nf_pre_routing+0x7e7/0x13a0 net/bridge/br_netfilter_hooks.c:506
 nf_hook_entry_hookfn include/linux/netfilter.h:119 [inline]
 nf_hook_slow+0xbf/0x1f0 net/netfilter/core.c:511
 nf_hook include/linux/netfilter.h:244 [inline]
 NF_HOOK include/linux/netfilter.h:287 [inline]
 br_handle_frame+0x95b/0x1450 net/bridge/br_input.c:305
 __netif_receive_skb_core+0xa96/0x3040 net/core/dev.c:4902
 __netif_receive_skb_one_core+0xa8/0x1a0 net/core/dev.c:4971
 __netif_receive_skb+0x2c/0x1c0 net/core/dev.c:5083
 netif_receive_skb_internal+0x117/0x660 net/core/dev.c:5186
 netif_receive_skb+0x6e/0x5a0 net/core/dev.c:5261

Fixes: ba5ea61462 ("bridge: simplify ip_mc_check_igmp() and ipv6_mc_check_mld() calls")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-09 19:52:47 -08:00
2019-03-05 10:00:35 -08:00
2019-02-21 11:41:19 +00:00
2019-03-03 15:21:29 -08:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

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.
Description
No description provided
Readme 7.9 GiB
Languages
C 97.7%
Assembly 1.6%
Makefile 0.3%
Perl 0.1%