kernel/git/stable/linux.git/net/rds, branch linux-2.6.32.y

RDS: fix race condition when sending a message on unbound socket

2016-01-29T21:12:39+00:00

commit 8c7188b23474cca017b3ef354c4a58456f68303a upstream. Sasha's found a NULL pointer dereference in the RDS connection code when sending a message to an apparently unbound socket. The problem is caused by the code checking if the socket is bound in rds_sendmsg(), which checks the rs_bound_addr field without taking a lock on the socket. This opens a race where rs_bound_addr is temporarily set but where the transport is not in rds_bind(), leading to a NULL pointer dereference when trying to dereference 'trans' in __rds_conn_create(). Vegard wrote a reproducer for this issue, so kindly ask him to share if you're interested. I cannot reproduce the NULL pointer dereference using Vegard's reproducer with this patch, whereas I could without. Complete earlier incomplete fix to CVE-2015-6937: 74e98eb08588 ("RDS: verify the underlying transport exists before creating a connection") Cc: David S. Miller Reviewed-by: Vegard Nossum Reviewed-by: Sasha Levin Acked-by: Santosh Shilimkar Signed-off-by: Quentin Casasnovas Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings Signed-off-by: Willy Tarreau

RDS-TCP: Recover correctly from pskb_pull()/pksb_trim() failure in rds_tcp_data_recv

2015-12-05T23:49:18+00:00

[ Upstream commit 8ce675ff39b9958d1c10f86cf58e357efaafc856 ] Either of pskb_pull() or pskb_trim() may fail under low memory conditions. If rds_tcp_data_recv() ignores such failures, the application will receive corrupted data because the skb has not been correctly carved to the RDS datagram size. Avoid this by handling pskb_pull/pskb_trim failure in the same manner as the skb_clone failure: bail out of rds_tcp_data_recv(), and retry via the deferred call to rds_send_worker() that gets set up on ENOMEM from rds_tcp_read_sock() Signed-off-by: Sowmini Varadhan Acked-by: Santosh Shilimkar Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings (cherry picked from commit f114d9374ba3e42c86b112c8b4dbcba50a7330e7) Signed-off-by: Willy Tarreau

RDS: verify the underlying transport exists before creating a connection

2015-12-05T23:49:12+00:00

commit 74e98eb085889b0d2d4908f59f6e00026063014f upstream. There was no verification that an underlying transport exists when creating a connection, this would cause dereferencing a NULL ptr. It might happen on sockets that weren't properly bound before attempting to send a message, which will cause a NULL ptr deref: [135546.047719] kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN [135546.051270] Modules linked in: [135546.051781] CPU: 4 PID: 15650 Comm: trinity-c4 Not tainted 4.2.0-next-20150902-sasha-00041-gbaa1222-dirty #2527 [135546.053217] task: ffff8800835bc000 ti: ffff8800bc708000 task.ti: ffff8800bc708000 [135546.054291] RIP: __rds_conn_create (net/rds/connection.c:194) [135546.055666] RSP: 0018:ffff8800bc70fab0 EFLAGS: 00010202 [135546.056457] RAX: dffffc0000000000 RBX: 0000000000000f2c RCX: ffff8800835bc000 [135546.057494] RDX: 0000000000000007 RSI: ffff8800835bccd8 RDI: 0000000000000038 [135546.058530] RBP: ffff8800bc70fb18 R08: 0000000000000001 R09: 0000000000000000 [135546.059556] R10: ffffed014d7a3a23 R11: ffffed014d7a3a21 R12: 0000000000000000 [135546.060614] R13: 0000000000000001 R14: ffff8801ec3d0000 R15: 0000000000000000 [135546.061668] FS: 00007faad4ffb700(0000) GS:ffff880252000000(0000) knlGS:0000000000000000 [135546.062836] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [135546.063682] CR2: 000000000000846a CR3: 000000009d137000 CR4: 00000000000006a0 [135546.064723] Stack: [135546.065048] ffffffffafe2055c ffffffffafe23fc1 ffffed00493097bf ffff8801ec3d0008 [135546.066247] 0000000000000000 00000000000000d0 0000000000000000 ac194a24c0586342 [135546.067438] 1ffff100178e1f78 ffff880320581b00 ffff8800bc70fdd0 ffff880320581b00 [135546.068629] Call Trace: [135546.069028] ? __rds_conn_create (include/linux/rcupdate.h:856 net/rds/connection.c:134) [135546.069989] ? rds_message_copy_from_user (net/rds/message.c:298) [135546.071021] rds_conn_create_outgoing (net/rds/connection.c:278) [135546.071981] rds_sendmsg (net/rds/send.c:1058) [135546.072858] ? perf_trace_lock (include/trace/events/lock.h:38) [135546.073744] ? lockdep_init (kernel/locking/lockdep.c:3298) [135546.074577] ? rds_send_drop_to (net/rds/send.c:976) [135546.075508] ? __might_fault (./arch/x86/include/asm/current.h:14 mm/memory.c:3795) [135546.076349] ? __might_fault (mm/memory.c:3795) [135546.077179] ? rds_send_drop_to (net/rds/send.c:976) [135546.078114] sock_sendmsg (net/socket.c:611 net/socket.c:620) [135546.078856] SYSC_sendto (net/socket.c:1657) [135546.079596] ? SYSC_connect (net/socket.c:1628) [135546.080510] ? trace_dump_stack (kernel/trace/trace.c:1926) [135546.081397] ? ring_buffer_unlock_commit (kernel/trace/ring_buffer.c:2479 kernel/trace/ring_buffer.c:2558 kernel/trace/ring_buffer.c:2674) [135546.082390] ? trace_buffer_unlock_commit (kernel/trace/trace.c:1749) [135546.083410] ? trace_event_raw_event_sys_enter (include/trace/events/syscalls.h:16) [135546.084481] ? do_audit_syscall_entry (include/trace/events/syscalls.h:16) [135546.085438] ? trace_buffer_unlock_commit (kernel/trace/trace.c:1749) [135546.085515] rds_ib_laddr_check(): addr 36.74.25.172 ret -99 node type -1 Acked-by: Santosh Shilimkar Signed-off-by: Sasha Levin Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings (cherry picked from commit 987ad6eef35223b149baf453171b74917c372cbc) Signed-off-by: Willy Tarreau

rds: fix an integer overflow test in rds_info_getsockopt()

2015-12-05T23:49:05+00:00

commit 468b732b6f76b138c0926eadf38ac88467dcd271 upstream. "len" is a signed integer. We check that len is not negative, so it goes from zero to INT_MAX. PAGE_SIZE is unsigned long so the comparison is type promoted to unsigned long. ULONG_MAX - 4095 is a higher than INT_MAX so the condition can never be true. I don't know if this is harmful but it seems safe to limit "len" to INT_MAX - 4095. Fixes: a8c879a7ee98 ('RDS: Info and stats') Signed-off-by: Dan Carpenter Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings (cherry picked from commit f3a66bdc88c3261f55b942453476e623056b92d9) Signed-off-by: Willy Tarreau

rds: avoid potential stack overflow

2015-05-24T08:10:49+00:00

[ Upstream commit f862e07cf95d5b62a5fc5e981dd7d0dbaf33a501 ] The rds_iw_update_cm_id function stores a large 'struct rds_sock' object on the stack in order to pass a pair of addresses. This happens to just fit withint the 1024 byte stack size warning limit on x86, but just exceed that limit on ARM, which gives us this warning: net/rds/iw_rdma.c:200:1: warning: the frame size of 1056 bytes is larger than 1024 bytes [-Wframe-larger-than=] As the use of this large variable is basically bogus, we can rearrange the code to not do that. Instead of passing an rds socket into rds_iw_get_device, we now just pass the two addresses that we have available in rds_iw_update_cm_id, and we change rds_iw_get_mr accordingly, to create two address structures on the stack there. Signed-off-by: Arnd Bergmann Acked-by: Sowmini Varadhan Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings (cherry picked from commit 3fe2d645fe4ea7ff6cba9020685e46c1a1dff9c0) Signed-off-by: Willy Tarreau

net: rds: use correct size for max unacked packets and bytes

2015-05-24T08:10:43+00:00

commit db27ebb111e9f69efece08e4cb6a34ff980f8896 upstream. Max unacked packets/bytes is an int while sizeof(long) was used in the sysctl table. This means that when they were getting read we'd also leak kernel memory to userspace along with the timeout values. Signed-off-by: Sasha Levin Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings (cherry picked from commit 3760b67b3e419b9ac42a45417491360a14a35357) Signed-off-by: Willy Tarreau

rds: prevent dereference of a NULL device in rds_iw_laddr_check

2014-05-19T05:54:18+00:00

[ Upstream commit bf39b4247b8799935ea91d90db250ab608a58e50 ] Binding might result in a NULL device which is later dereferenced without checking. Signed-off-by: Sasha Levin Signed-off-by: David S. Miller Signed-off-by: Willy Tarreau

rds: prevent dereference of a NULL device

2014-05-19T05:54:09+00:00

[ Upstream commit c2349758acf1874e4c2b93fe41d072336f1a31d0 ] Binding might result in a NULL device, which is dereferenced causing this BUG: [ 1317.260548] BUG: unable to handle kernel NULL pointer dereference at 000000000000097 4 [ 1317.261847] IP: [] rds_ib_laddr_check+0x82/0x110 [ 1317.263315] PGD 418bcb067 PUD 3ceb21067 PMD 0 [ 1317.263502] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [ 1317.264179] Dumping ftrace buffer: [ 1317.264774] (ftrace buffer empty) [ 1317.265220] Modules linked in: [ 1317.265824] CPU: 4 PID: 836 Comm: trinity-child46 Tainted: G W 3.13.0-rc4- next-20131218-sasha-00013-g2cebb9b-dirty #4159 [ 1317.267415] task: ffff8803ddf33000 ti: ffff8803cd31a000 task.ti: ffff8803cd31a000 [ 1317.268399] RIP: 0010:[] [] rds_ib_laddr_check+ 0x82/0x110 [ 1317.269670] RSP: 0000:ffff8803cd31bdf8 EFLAGS: 00010246 [ 1317.270230] RAX: 0000000000000000 RBX: ffff88020b0dd388 RCX: 0000000000000000 [ 1317.270230] RDX: ffffffff8439822e RSI: 00000000000c000a RDI: 0000000000000286 [ 1317.270230] RBP: ffff8803cd31be38 R08: 0000000000000000 R09: 0000000000000000 [ 1317.270230] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 [ 1317.270230] R13: 0000000054086700 R14: 0000000000a25de0 R15: 0000000000000031 [ 1317.270230] FS: 00007ff40251d700(0000) GS:ffff88022e200000(0000) knlGS:000000000000 0000 [ 1317.270230] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 1317.270230] CR2: 0000000000000974 CR3: 00000003cd478000 CR4: 00000000000006e0 [ 1317.270230] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1317.270230] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000090602 [ 1317.270230] Stack: [ 1317.270230] 0000000054086700 5408670000a25de0 5408670000000002 0000000000000000 [ 1317.270230] ffffffff84223542 00000000ea54c767 0000000000000000 ffffffff86d26160 [ 1317.270230] ffff8803cd31be68 ffffffff84223556 ffff8803cd31beb8 ffff8800c6765280 [ 1317.270230] Call Trace: [ 1317.270230] [] ? rds_trans_get_preferred+0x42/0xa0 [ 1317.270230] [] rds_trans_get_preferred+0x56/0xa0 [ 1317.270230] [] rds_bind+0x73/0xf0 [ 1317.270230] [] SYSC_bind+0x92/0xf0 [ 1317.270230] [] ? context_tracking_user_exit+0xb8/0x1d0 [ 1317.270230] [] ? trace_hardirqs_on+0xd/0x10 [ 1317.270230] [] ? syscall_trace_enter+0x32/0x290 [ 1317.270230] [] SyS_bind+0xe/0x10 [ 1317.270230] [] tracesys+0xdd/0xe2 [ 1317.270230] Code: 00 8b 45 cc 48 8d 75 d0 48 c7 45 d8 00 00 00 00 66 c7 45 d0 02 00 89 45 d4 48 89 df e8 78 49 76 ff 41 89 c4 85 c0 75 0c 48 8b 03 <80> b8 74 09 00 00 01 7 4 06 41 bc 9d ff ff ff f6 05 2a b6 c2 02 [ 1317.270230] RIP [] rds_ib_laddr_check+0x82/0x110 [ 1317.270230] RSP [ 1317.270230] CR2: 0000000000000974 Signed-off-by: Sasha Levin Signed-off-by: David S. Miller Signed-off-by: Willy Tarreau

net: rework recvmsg handler msg_name and msg_namelen logic

2014-05-19T05:54:00+00:00

CVE-2013-7266 BugLink: http://bugs.launchpad.net/bugs/1267081 This patch now always passes msg->msg_namelen as 0. recvmsg handlers must set msg_namelen to the proper size <= sizeof(struct sockaddr_storage) to return msg_name to the user. This prevents numerous uninitialized memory leaks we had in the recvmsg handlers and makes it harder for new code to accidentally leak uninitialized memory. Optimize for the case recvfrom is called with NULL as address. We don't need to copy the address at all, so set it to NULL before invoking the recvmsg handler. We can do so, because all the recvmsg handlers must cope with the case a plain read() is called on them. read() also sets msg_name to NULL. Also document these changes in include/linux/net.h as suggested by David Miller. Changes since RFC: Set msg->msg_name = NULL if user specified a NULL in msg_name but had a non-null msg_namelen in verify_iovec/verify_compat_iovec. This doesn't affect sendto as it would bail out earlier while trying to copy-in the address. It also more naturally reflects the logic by the callers of verify_iovec. With this change in place I could remove " if (!uaddr || msg_sys->msg_namelen == 0) msg->msg_name = NULL ". This change does not alter the user visible error logic as we ignore msg_namelen as long as msg_name is NULL. Also remove two unnecessary curly brackets in ___sys_recvmsg and change comments to netdev style. Cc: David Miller Suggested-by: Eric Dumazet Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller (back ported from commit f3d3342602f8bcbf37d7c46641cb9bca7618eb1c) Signed-off-by: Luis Henriques Acked-by: Andy Whitcroft Acked-by: Stefan Bader Signed-off-by: Tim Gardner Signed-off-by: Willy Tarreau

rds: set correct msg_namelen

2013-06-10T09:43:44+00:00

commit 06b6a1cf6e776426766298d055bb3991957d90a7 upstream Jay Fenlason (fenlason@redhat.com) found a bug, that recvfrom() on an RDS socket can return the contents of random kernel memory to userspace if it was called with a address length larger than sizeof(struct sockaddr_in). rds_recvmsg() also fails to set the addr_len paramater properly before returning, but that's just a bug. There are also a number of cases wher recvfrom() can return an entirely bogus address. Anything in rds_recvmsg() that returns a non-negative value but does not go through the "sin = (struct sockaddr_in *)msg->msg_name;" code path at the end of the while(1) loop will return up to 128 bytes of kernel memory to userspace. And I write two test programs to reproduce this bug, you will see that in rds_server, fromAddr will be overwritten and the following sock_fd will be destroyed. Yes, it is the programmer's fault to set msg_namelen incorrectly, but it is better to make the kernel copy the real length of address to user space in such case. How to run the test programs ? I test them on 32bit x86 system, 3.5.0-rc7. 1 compile gcc -o rds_client rds_client.c gcc -o rds_server rds_server.c 2 run ./rds_server on one console 3 run ./rds_client on another console 4 you will see something like: server is waiting to receive data... old socket fd=3 server received data from client:data from client msg.msg_namelen=32 new socket fd=-1067277685 sendmsg() : Bad file descriptor /***************** rds_client.c ********************/ int main(void) { int sock_fd; struct sockaddr_in serverAddr; struct sockaddr_in toAddr; char recvBuffer[128] = "data from client"; struct msghdr msg; struct iovec iov; sock_fd = socket(AF_RDS, SOCK_SEQPACKET, 0); if (sock_fd < 0) { perror("create socket error\n"); exit(1); } memset(&serverAddr, 0, sizeof(serverAddr)); serverAddr.sin_family = AF_INET; serverAddr.sin_addr.s_addr = inet_addr("127.0.0.1"); serverAddr.sin_port = htons(4001); if (bind(sock_fd, (struct sockaddr*)&serverAddr, sizeof(serverAddr)) < 0) { perror("bind() error\n"); close(sock_fd); exit(1); } memset(&toAddr, 0, sizeof(toAddr)); toAddr.sin_family = AF_INET; toAddr.sin_addr.s_addr = inet_addr("127.0.0.1"); toAddr.sin_port = htons(4000); msg.msg_name = &toAddr; msg.msg_namelen = sizeof(toAddr); msg.msg_iov = &iov; msg.msg_iovlen = 1; msg.msg_iov->iov_base = recvBuffer; msg.msg_iov->iov_len = strlen(recvBuffer) + 1; msg.msg_control = 0; msg.msg_controllen = 0; msg.msg_flags = 0; if (sendmsg(sock_fd, &msg, 0) == -1) { perror("sendto() error\n"); close(sock_fd); exit(1); } printf("client send data:%s\n", recvBuffer); memset(recvBuffer, '\0', 128); msg.msg_name = &toAddr; msg.msg_namelen = sizeof(toAddr); msg.msg_iov = &iov; msg.msg_iovlen = 1; msg.msg_iov->iov_base = recvBuffer; msg.msg_iov->iov_len = 128; msg.msg_control = 0; msg.msg_controllen = 0; msg.msg_flags = 0; if (recvmsg(sock_fd, &msg, 0) == -1) { perror("recvmsg() error\n"); close(sock_fd); exit(1); } printf("receive data from server:%s\n", recvBuffer); close(sock_fd); return 0; } /***************** rds_server.c ********************/ int main(void) { struct sockaddr_in fromAddr; int sock_fd; struct sockaddr_in serverAddr; unsigned int addrLen; char recvBuffer[128]; struct msghdr msg; struct iovec iov; sock_fd = socket(AF_RDS, SOCK_SEQPACKET, 0); if(sock_fd < 0) { perror("create socket error\n"); exit(0); } memset(&serverAddr, 0, sizeof(serverAddr)); serverAddr.sin_family = AF_INET; serverAddr.sin_addr.s_addr = inet_addr("127.0.0.1"); serverAddr.sin_port = htons(4000); if (bind(sock_fd, (struct sockaddr*)&serverAddr, sizeof(serverAddr)) < 0) { perror("bind error\n"); close(sock_fd); exit(1); } printf("server is waiting to receive data...\n"); msg.msg_name = &fromAddr; /* * I add 16 to sizeof(fromAddr), ie 32, * and pay attention to the definition of fromAddr, * recvmsg() will overwrite sock_fd, * since kernel will copy 32 bytes to userspace. * * If you just use sizeof(fromAddr), it works fine. * */ msg.msg_namelen = sizeof(fromAddr) + 16; /* msg.msg_namelen = sizeof(fromAddr); */ msg.msg_iov = &iov; msg.msg_iovlen = 1; msg.msg_iov->iov_base = recvBuffer; msg.msg_iov->iov_len = 128; msg.msg_control = 0; msg.msg_controllen = 0; msg.msg_flags = 0; while (1) { printf("old socket fd=%d\n", sock_fd); if (recvmsg(sock_fd, &msg, 0) == -1) { perror("recvmsg() error\n"); close(sock_fd); exit(1); } printf("server received data from client:%s\n", recvBuffer); printf("msg.msg_namelen=%d\n", msg.msg_namelen); printf("new socket fd=%d\n", sock_fd); strcat(recvBuffer, "--data from server"); if (sendmsg(sock_fd, &msg, 0) == -1) { perror("sendmsg()\n"); close(sock_fd); exit(1); } } close(sock_fd); return 0; } Signed-off-by: Weiping Pan Signed-off-by: David S. Miller [dannf: Adjusted to apply to Debian's 2.6.32] Signed-off-by: Willy Tarreau