From: Eric Dumazet edumazet@google.com
[ Upstream commit 3580d04aa674383c42de7b635d28e52a1e5bc72c ]
syzbot reported memory leaks [1] that I have back tracked to a missing cleanup from igmpv3_del_delrec() when (im->sfmode != MCAST_INCLUDE)
Add ip_sf_list_clear_all() and kfree_pmc() helpers to explicitely handle the cleanups before freeing.
[1]
BUG: memory leak unreferenced object 0xffff888123e32b00 (size 64): comm "softirq", pid 0, jiffies 4294942968 (age 8.010s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 e0 00 00 01 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<000000006105011b>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline] [<000000006105011b>] slab_post_alloc_hook mm/slab.h:439 [inline] [<000000006105011b>] slab_alloc mm/slab.c:3326 [inline] [<000000006105011b>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553 [<000000004bba8073>] kmalloc include/linux/slab.h:547 [inline] [<000000004bba8073>] kzalloc include/linux/slab.h:742 [inline] [<000000004bba8073>] ip_mc_add1_src net/ipv4/igmp.c:1961 [inline] [<000000004bba8073>] ip_mc_add_src+0x36b/0x400 net/ipv4/igmp.c:2085 [<00000000a46a65a0>] ip_mc_msfilter+0x22d/0x310 net/ipv4/igmp.c:2475 [<000000005956ca89>] do_ip_setsockopt.isra.0+0x1795/0x1930 net/ipv4/ip_sockglue.c:957 [<00000000848e2d2f>] ip_setsockopt+0x3b/0xb0 net/ipv4/ip_sockglue.c:1246 [<00000000b9db185c>] udp_setsockopt+0x4e/0x90 net/ipv4/udp.c:2616 [<000000003028e438>] sock_common_setsockopt+0x38/0x50 net/core/sock.c:3130 [<0000000015b65589>] __sys_setsockopt+0x98/0x120 net/socket.c:2078 [<00000000ac198ef0>] __do_sys_setsockopt net/socket.c:2089 [inline] [<00000000ac198ef0>] __se_sys_setsockopt net/socket.c:2086 [inline] [<00000000ac198ef0>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2086 [<000000000a770437>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301 [<00000000d3adb93b>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes: 9c8bb163ae78 ("igmp, mld: Fix memory leak in igmpv3/mld_del_delrec()") Signed-off-by: Eric Dumazet edumazet@google.com Cc: Hangbin Liu liuhangbin@gmail.com Reported-by: syzbot syzkaller@googlegroups.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/igmp.c | 47 ++++++++++++++++++++++++++++++----------------- 1 file changed, 30 insertions(+), 17 deletions(-)
--- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -635,6 +635,24 @@ static void igmpv3_clear_zeros(struct ip } }
+static void ip_sf_list_clear_all(struct ip_sf_list *psf) +{ + struct ip_sf_list *next; + + while (psf) { + next = psf->sf_next; + kfree(psf); + psf = next; + } +} + +static void kfree_pmc(struct ip_mc_list *pmc) +{ + ip_sf_list_clear_all(pmc->sources); + ip_sf_list_clear_all(pmc->tomb); + kfree(pmc); +} + static void igmpv3_send_cr(struct in_device *in_dev) { struct ip_mc_list *pmc, *pmc_prev, *pmc_next; @@ -671,7 +689,7 @@ static void igmpv3_send_cr(struct in_dev else in_dev->mc_tomb = pmc_next; in_dev_put(pmc->interface); - kfree(pmc); + kfree_pmc(pmc); } else pmc_prev = pmc; } @@ -1195,12 +1213,16 @@ static void igmpv3_del_delrec(struct in_ im->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv; if (im->sfmode == MCAST_INCLUDE) { im->tomb = pmc->tomb; + pmc->tomb = NULL; + im->sources = pmc->sources; + pmc->sources = NULL; + for (psf = im->sources; psf; psf = psf->sf_next) psf->sf_crcount = im->crcount; } in_dev_put(pmc->interface); - kfree(pmc); + kfree_pmc(pmc); } spin_unlock_bh(&im->lock); } @@ -1221,21 +1243,18 @@ static void igmpv3_clear_delrec(struct i nextpmc = pmc->next; ip_mc_clear_src(pmc); in_dev_put(pmc->interface); - kfree(pmc); + kfree_pmc(pmc); } /* clear dead sources, too */ rcu_read_lock(); for_each_pmc_rcu(in_dev, pmc) { - struct ip_sf_list *psf, *psf_next; + struct ip_sf_list *psf;
spin_lock_bh(&pmc->lock); psf = pmc->tomb; pmc->tomb = NULL; spin_unlock_bh(&pmc->lock); - for (; psf; psf = psf_next) { - psf_next = psf->sf_next; - kfree(psf); - } + ip_sf_list_clear_all(psf); } rcu_read_unlock(); } @@ -2099,7 +2118,7 @@ static int ip_mc_add_src(struct in_devic
static void ip_mc_clear_src(struct ip_mc_list *pmc) { - struct ip_sf_list *psf, *nextpsf, *tomb, *sources; + struct ip_sf_list *tomb, *sources;
spin_lock_bh(&pmc->lock); tomb = pmc->tomb; @@ -2111,14 +2130,8 @@ static void ip_mc_clear_src(struct ip_mc pmc->sfcount[MCAST_EXCLUDE] = 1; spin_unlock_bh(&pmc->lock);
- for (psf = tomb; psf; psf = nextpsf) { - nextpsf = psf->sf_next; - kfree(psf); - } - for (psf = sources; psf; psf = nextpsf) { - nextpsf = psf->sf_next; - kfree(psf); - } + ip_sf_list_clear_all(tomb); + ip_sf_list_clear_all(sources); }
/* Join a multicast group