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authorEric Dumazet <edumazet@google.com>2018-05-02 14:53:39 -0700
committerDavid S. Miller <davem@davemloft.net>2018-05-03 11:26:14 -0400
commiteb80ca476ec11f67a62691a93604b405ffc7d80c (patch)
treebffc1eb7a4eb807f3e883bb6064de1f34e346285 /net/rds/recv.c
parent5697db4a696c41601a1d15c1922150b4dbf5726c (diff)
downloadlinux-stericsson-eb80ca476ec11f67a62691a93604b405ffc7d80c.tar.gz
rds: do not leak kernel memory to user land
syzbot/KMSAN reported an uninit-value in put_cmsg(), originating from rds_cmsg_recv(). Simply clear the structure, since we have holes there, or since rx_traces might be smaller than RDS_MSG_RX_DGRAM_TRACE_MAX. BUG: KMSAN: uninit-value in copy_to_user include/linux/uaccess.h:184 [inline] BUG: KMSAN: uninit-value in put_cmsg+0x600/0x870 net/core/scm.c:242 CPU: 0 PID: 4459 Comm: syz-executor582 Not tainted 4.16.0+ #87 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:53 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 kmsan_internal_check_memory+0x135/0x1e0 mm/kmsan/kmsan.c:1157 kmsan_copy_to_user+0x69/0x160 mm/kmsan/kmsan.c:1199 copy_to_user include/linux/uaccess.h:184 [inline] put_cmsg+0x600/0x870 net/core/scm.c:242 rds_cmsg_recv net/rds/recv.c:570 [inline] rds_recvmsg+0x2db5/0x3170 net/rds/recv.c:657 sock_recvmsg_nosec net/socket.c:803 [inline] sock_recvmsg+0x1d0/0x230 net/socket.c:810 ___sys_recvmsg+0x3fb/0x810 net/socket.c:2205 __sys_recvmsg net/socket.c:2250 [inline] SYSC_recvmsg+0x298/0x3c0 net/socket.c:2262 SyS_recvmsg+0x54/0x80 net/socket.c:2257 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 Fixes: 3289025aedc0 ("RDS: add receive message trace used by application") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Santosh Shilimkar <santosh.shilimkar@oracle.com> Cc: linux-rdma <linux-rdma@vger.kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/rds/recv.c')
-rw-r--r--net/rds/recv.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/net/rds/recv.c b/net/rds/recv.c
index de50e2126e40..dc67458b52f0 100644
--- a/net/rds/recv.c
+++ b/net/rds/recv.c
@@ -558,6 +558,7 @@ static int rds_cmsg_recv(struct rds_incoming *inc, struct msghdr *msg,
struct rds_cmsg_rx_trace t;
int i, j;
+ memset(&t, 0, sizeof(t));
inc->i_rx_lat_trace[RDS_MSG_RX_CMSG] = local_clock();
t.rx_traces = rs->rs_rx_traces;
for (i = 0; i < rs->rs_rx_traces; i++) {