mld: fix memory leak in mld_del_delrec()
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>
Signed-off-by: David S. Miller <davem@davemloft.net>