From: Liu Jian
mainline inclusion
from mainline-net-next
commit 23d2b94043ca8835bd1e67749020e839f396a1c2
category: bugfix
issue: #I3ZXZF
CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?...
--------------------------------
I got below panic when doing fuzz test:
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 4056 Comm: syz-executor.3 Tainted: G B 5.14.0-rc1-00195-gcff5c4254439-dirty #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack_lvl+0x7a/0x9b
panic+0x2cd/0x5af
end_report.cold+0x5a/0x5a
kasan_report+0xec/0x110
ip_check_mc_rcu+0x556/0x5d0
__mkroute_output+0x895/0x1740
ip_route_output_key_hash_rcu+0x2d0/0x1050
ip_route_output_key_hash+0x182/0x2e0
ip_route_output_flow+0x28/0x130
udp_sendmsg+0x165d/0x2280
udpv6_sendmsg+0x121e/0x24f0
inet6_sendmsg+0xf7/0x140
sock_sendmsg+0xe9/0x180
____sys_sendmsg+0x2b8/0x7a0
___sys_sendmsg+0xf0/0x160
__sys_sendmmsg+0x17e/0x3c0
__x64_sys_sendmmsg+0x9e/0x100
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x462eb9
Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8
48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48>
3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3df5af1c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000462eb9
RDX: 0000000000000312 RSI: 0000000020001700 RDI: 0000000000000007
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3df5af26bc
R13: 00000000004c372d R14: 0000000000700b10 R15: 00000000ffffffff
It is one use-after-free in ip_check_mc_rcu.
In ip_mc_del_src, the ip_sf_list of pmc has been freed under pmc->lock protection.
But access to ip_sf_list in ip_check_mc_rcu is not protected by the lock.
Signed-off-by: Liu Jian
Signed-off-by: David S. Miller
Signed-off-by: Liu Jian
Reviewed-by: Yue Haibing
Signed-off-by: Chen Jun
Signed-off-by: Yu Changchun
---
net/ipv4/igmp.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 6b3c558a4f23..03589a04f9aa 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -2713,6 +2713,7 @@ int ip_check_mc_rcu(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u
rv = 1;
} else if (im) {
if (src_addr) {
+ spin_lock_bh(&im->lock);
for (psf = im->sources; psf; psf = psf->sf_next) {
if (psf->sf_inaddr == src_addr)
break;
@@ -2723,6 +2724,7 @@ int ip_check_mc_rcu(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u
im->sfcount[MCAST_EXCLUDE];
else
rv = im->sfcount[MCAST_EXCLUDE] != 0;
+ spin_unlock_bh(&im->lock);
} else
rv = 1; /* unspecified source; tentatively allow */
}
--
2.22.0
