From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>
Cc: netdev <netdev@vger.kernel.org>,
Eric Dumazet <edumazet@google.com>,
Eric Dumazet <eric.dumazet@gmail.com>,
syzbot <syzkaller@googlegroups.com>
Subject: [PATCH net] mld: fix memory leak in mld_del_delrec()
Date: Tue, 27 Aug 2019 03:33:12 -0700 [thread overview]
Message-ID: <20190827103312.180258-1-edumazet@google.com> (raw)
Similar to the fix done for IPv4 in commit e5b1c6c6277d
("igmp: fix memory leak in igmpv3_del_delrec()"), we need to
make sure mca_tomb and mca_sources are not blindly overwritten.
Using swap() then a call to ip6_mc_clear_src() will take care
of the missing free.
BUG: memory leak
unreferenced object 0xffff888117d9db00 (size 64):
comm "syz-executor247", pid 6918, jiffies 4294943989 (age 25.350s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 fe 88 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<000000005b463030>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline]
[<000000005b463030>] slab_post_alloc_hook mm/slab.h:522 [inline]
[<000000005b463030>] slab_alloc mm/slab.c:3319 [inline]
[<000000005b463030>] kmem_cache_alloc_trace+0x145/0x2c0 mm/slab.c:3548
[<00000000939cbf94>] kmalloc include/linux/slab.h:552 [inline]
[<00000000939cbf94>] kzalloc include/linux/slab.h:748 [inline]
[<00000000939cbf94>] ip6_mc_add1_src net/ipv6/mcast.c:2236 [inline]
[<00000000939cbf94>] ip6_mc_add_src+0x31f/0x420 net/ipv6/mcast.c:2356
[<00000000d8972221>] ip6_mc_source+0x4a8/0x600 net/ipv6/mcast.c:449
[<000000002b203d0d>] do_ipv6_setsockopt.isra.0+0x1b92/0x1dd0 net/ipv6/ipv6_sockglue.c:748
[<000000001f1e2d54>] ipv6_setsockopt+0x89/0xd0 net/ipv6/ipv6_sockglue.c:944
[<00000000c8f7bdf9>] udpv6_setsockopt+0x4e/0x90 net/ipv6/udp.c:1558
[<000000005a9a0c5e>] sock_common_setsockopt+0x38/0x50 net/core/sock.c:3139
[<00000000910b37b2>] __sys_setsockopt+0x10f/0x220 net/socket.c:2084
[<00000000e9108023>] __do_sys_setsockopt net/socket.c:2100 [inline]
[<00000000e9108023>] __se_sys_setsockopt net/socket.c:2097 [inline]
[<00000000e9108023>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2097
[<00000000f4818160>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:296
[<000000008d367e8f>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes: 1666d49e1d41 ("mld: do not remove mld souce list info when set link down")
Fixes: 9c8bb163ae78 ("igmp, mld: Fix memory leak in igmpv3/mld_del_delrec()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
---
net/ipv6/mcast.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 7f3f13c3791636f92c5c46aa6235c69682dea151..eaa4c2cc2fbb2e784b5641135d28dd38a0616421 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -787,14 +787,15 @@ static void mld_del_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im)
if (pmc) {
im->idev = pmc->idev;
if (im->mca_sfmode == MCAST_INCLUDE) {
- im->mca_tomb = pmc->mca_tomb;
- im->mca_sources = pmc->mca_sources;
+ swap(im->mca_tomb, pmc->mca_tomb);
+ swap(im->mca_sources, pmc->mca_sources);
for (psf = im->mca_sources; psf; psf = psf->sf_next)
psf->sf_crcount = idev->mc_qrv;
} else {
im->mca_crcount = idev->mc_qrv;
}
in6_dev_put(pmc->idev);
+ ip6_mc_clear_src(pmc);
kfree(pmc);
}
spin_unlock_bh(&im->mca_lock);
--
2.23.0.187.g17f5b7556c-goog
next reply other threads:[~2019-08-27 10:33 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-27 10:33 Eric Dumazet [this message]
2019-08-28 21:48 ` [PATCH net] mld: fix memory leak in mld_del_delrec() David Miller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190827103312.180258-1-edumazet@google.com \
--to=edumazet@google.com \
--cc=davem@davemloft.net \
--cc=eric.dumazet@gmail.com \
--cc=netdev@vger.kernel.org \
--cc=syzkaller@googlegroups.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox