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| author | Eric Dumazet <edumazet@google.com> | 2021-11-03 16:49:11 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-11-04 11:28:04 +0000 |
| commit | d00c8ee31729248ba40b4ab25cd3b3b580c6f87c (patch) | |
| tree | c6c9c306238f953df639491afd1e27000041f1e6 /net/core/sock.c | |
| parent | 3b65abb8d8a650e50ff5448ac38992ef8a74c584 (diff) | |
| download | linux-d00c8ee31729248ba40b4ab25cd3b3b580c6f87c.tar.bz2 | |
net: fix possible NULL deref in sock_reserve_memory
Sanity check in sock_reserve_memory() was not enough to prevent malicious
user to trigger a NULL deref.
In this case, the isse is that sk_prot->memory_allocated is NULL.
Use standard sk_has_account() helper to deal with this.
BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: null-ptr-deref in atomic_long_add_return include/linux/atomic/atomic-instrumented.h:1218 [inline]
BUG: KASAN: null-ptr-deref in sk_memory_allocated_add include/net/sock.h:1371 [inline]
BUG: KASAN: null-ptr-deref in sock_reserve_memory net/core/sock.c:994 [inline]
BUG: KASAN: null-ptr-deref in sock_setsockopt+0x22ab/0x2b30 net/core/sock.c:1443
Write of size 8 at addr 0000000000000000 by task syz-executor.0/11270
CPU: 1 PID: 11270 Comm: syz-executor.0 Not tainted 5.15.0-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
__kasan_report mm/kasan/report.c:446 [inline]
kasan_report.cold+0x66/0xdf mm/kasan/report.c:459
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
atomic_long_add_return include/linux/atomic/atomic-instrumented.h:1218 [inline]
sk_memory_allocated_add include/net/sock.h:1371 [inline]
sock_reserve_memory net/core/sock.c:994 [inline]
sock_setsockopt+0x22ab/0x2b30 net/core/sock.c:1443
__sys_setsockopt+0x4f8/0x610 net/socket.c:2172
__do_sys_setsockopt net/socket.c:2187 [inline]
__se_sys_setsockopt net/socket.c:2184 [inline]
__x64_sys_setsockopt+0xba/0x150 net/socket.c:2184
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f56076d5ae9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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:00007f5604c4b188 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f56077e8f60 RCX: 00007f56076d5ae9
RDX: 0000000000000049 RSI: 0000000000000001 RDI: 0000000000000003
RBP: 00007f560772ff25 R08: 000000000000fec7 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffb61a100f R14: 00007f5604c4b300 R15: 0000000000022000
</TASK>
Fixes: 2bb2f5fb21b0 ("net: add new socket option SO_RESERVE_MEM")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/sock.c')
| -rw-r--r-- | net/core/sock.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/sock.c b/net/core/sock.c index 9862eefce21e..8f2b2f2c0e7b 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -976,7 +976,7 @@ static int sock_reserve_memory(struct sock *sk, int bytes) bool charged; int pages; - if (!mem_cgroup_sockets_enabled || !sk->sk_memcg) + if (!mem_cgroup_sockets_enabled || !sk->sk_memcg || !sk_has_account(sk)) return -EOPNOTSUPP; if (!bytes) |