user/sven/linux.git/net/sctp/socket.c, branch v3.0.97

net: sctp: fix NULL pointer dereference in socket destruction

2013-06-27T17:34:33Z

[ Upstream commit 1abd165ed757db1afdefaac0a4bc8a70f97d258c ] While stress testing sctp sockets, I hit the following panic: BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 IP: [] sctp_endpoint_free+0xe/0x40 [sctp] PGD 7cead067 PUD 7ce76067 PMD 0 Oops: 0000 [#1] SMP Modules linked in: sctp(F) libcrc32c(F) [...] CPU: 7 PID: 2950 Comm: acc Tainted: GF 3.10.0-rc2+ #1 Hardware name: Dell Inc. PowerEdge T410/0H19HD, BIOS 1.6.3 02/01/2011 task: ffff88007ce0e0c0 ti: ffff88007b568000 task.ti: ffff88007b568000 RIP: 0010:[] [] sctp_endpoint_free+0xe/0x40 [sctp] RSP: 0018:ffff88007b569e08 EFLAGS: 00010292 RAX: 0000000000000000 RBX: ffff88007db78a00 RCX: dead000000200200 RDX: ffffffffa049fdb0 RSI: ffff8800379baf38 RDI: 0000000000000000 RBP: ffff88007b569e18 R08: ffff88007c230da0 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff880077990d00 R14: 0000000000000084 R15: ffff88007db78a00 FS: 00007fc18ab61700(0000) GS:ffff88007fc60000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000020 CR3: 000000007cf9d000 CR4: 00000000000007e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffff88007b569e38 ffff88007db78a00 ffff88007b569e38 ffffffffa049fded ffffffff81abf0c0 ffff88007db78a00 ffff88007b569e58 ffffffff8145b60e 0000000000000000 0000000000000000 ffff88007b569eb8 ffffffff814df36e Call Trace: [] sctp_destroy_sock+0x3d/0x80 [sctp] [] sk_common_release+0x1e/0xf0 [] inet_create+0x2ae/0x350 [] __sock_create+0x11f/0x240 [] sock_create+0x30/0x40 [] SyS_socket+0x4c/0xc0 [] ? do_page_fault+0xe/0x10 [] ? page_fault+0x22/0x30 [] system_call_fastpath+0x16/0x1b Code: 0c c9 c3 66 2e 0f 1f 84 00 00 00 00 00 e8 fb fe ff ff c9 c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 53 48 83 ec 08 66 66 66 66 90 <48> 8b 47 20 48 89 fb c6 47 1c 01 c6 40 12 07 e8 9e 68 01 00 48 RIP [] sctp_endpoint_free+0xe/0x40 [sctp] RSP CR2: 0000000000000020 ---[ end trace e0d71ec1108c1dd9 ]--- I did not hit this with the lksctp-tools functional tests, but with a small, multi-threaded test program, that heavily allocates, binds, listens and waits in accept on sctp sockets, and then randomly kills some of them (no need for an actual client in this case to hit this). Then, again, allocating, binding, etc, and then killing child processes. This panic then only occurs when ``echo 1 > /proc/sys/net/sctp/auth_enable'' is set. The cause for that is actually very simple: in sctp_endpoint_init() we enter the path of sctp_auth_init_hmacs(). There, we try to allocate our crypto transforms through crypto_alloc_hash(). In our scenario, it then can happen that crypto_alloc_hash() fails with -EINTR from crypto_larval_wait(), thus we bail out and release the socket via sk_common_release(), sctp_destroy_sock() and hit the NULL pointer dereference as soon as we try to access members in the endpoint during sctp_endpoint_free(), since endpoint at that time is still NULL. Now, if we have that case, we do not need to do any cleanup work and just leave the destruction handler. Signed-off-by: Daniel Borkmann Acked-by: Neil Horman Acked-by: Vlad Yasevich Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: sctp: sctp_setsockopt_auth_key: use kzfree instead of kfree

2013-02-14T18:47:35Z

[ Upstream commit 6ba542a291a5e558603ac51cda9bded347ce7627 ] In sctp_setsockopt_auth_key, we create a temporary copy of the user passed shared auth key for the endpoint or association and after internal setup, we free it right away. Since it's sensitive data, we should zero out the key before returning the memory back to the allocator. Thus, use kzfree instead of kfree, just as we do in sctp_auth_key_put(). Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: fix -ENOMEM result with invalid user space pointer in sendto() syscall

2013-01-11T17:03:35Z

[ Upstream commit 6e51fe7572590d8d86e93b547fab6693d305fd0d ] Consider the following program, that sets the second argument to the sendto() syscall incorrectly: #include #include #include int main(void) { int fd; struct sockaddr_in sa; fd = socket(AF_INET, SOCK_STREAM, 132 /*IPPROTO_SCTP*/); if (fd < 0) return 1; memset(&sa, 0, sizeof(sa)); sa.sin_family = AF_INET; sa.sin_addr.s_addr = inet_addr("127.0.0.1"); sa.sin_port = htons(11111); sendto(fd, NULL, 1, 0, (struct sockaddr *)&sa, sizeof(sa)); return 0; } We get -ENOMEM: $ strace -e sendto ./demo sendto(3, NULL, 1, 0, {sa_family=AF_INET, sin_port=htons(11111), sin_addr=inet_addr("127.0.0.1")}, 16) = -1 ENOMEM (Cannot allocate memory) Propagate the error code from sctp_user_addto_chunk(), so that we will tell user space what actually went wrong: $ strace -e sendto ./demo sendto(3, NULL, 1, 0, {sa_family=AF_INET, sin_port=htons(11111), sin_addr=inet_addr("127.0.0.1")}, 16) = -1 EFAULT (Bad address) Noticed while running Trinity (the syscall fuzzer). Signed-off-by: Tommi Rantala Acked-by: Vlad Yasevich Acked-by: Neil Horman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: Fix list corruption resulting from freeing an association on a list

2012-08-09T15:27:51Z

[ Upstream commit 2eebc1e188e9e45886ee00662519849339884d6d ] A few days ago Dave Jones reported this oops: [22766.294255] general protection fault: 0000 [#1] PREEMPT SMP [22766.295376] CPU 0 [22766.295384] Modules linked in: [22766.387137] ffffffffa169f292 6b6b6b6b6b6b6b6b ffff880147c03a90 ffff880147c03a74 [22766.387135] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 00000000000 [22766.387136] Process trinity-watchdo (pid: 10896, threadinfo ffff88013e7d2000, [22766.387137] Stack: [22766.387140] ffff880147c03a10 [22766.387140] ffffffffa169f2b6 [22766.387140] ffff88013ed95728 [22766.387143] 0000000000000002 [22766.387143] 0000000000000000 [22766.387143] ffff880003fad062 [22766.387144] ffff88013c120000 [22766.387144] [22766.387145] Call Trace: [22766.387145] [22766.387150] [] ? __sctp_lookup_association+0x62/0xd0 [sctp] [22766.387154] [] __sctp_lookup_association+0x86/0xd0 [sctp] [22766.387157] [] sctp_rcv+0x207/0xbb0 [sctp] [22766.387161] [] ? trace_hardirqs_off_caller+0x28/0xd0 [22766.387163] [] ? nf_hook_slow+0x133/0x210 [22766.387166] [] ? ip_local_deliver_finish+0x4c/0x4c0 [22766.387168] [] ip_local_deliver_finish+0x18d/0x4c0 [22766.387169] [] ? ip_local_deliver_finish+0x4c/0x4c0 [22766.387171] [] ip_local_deliver+0x47/0x80 [22766.387172] [] ip_rcv_finish+0x150/0x680 [22766.387174] [] ip_rcv+0x214/0x320 [22766.387176] [] __netif_receive_skb+0x7b7/0x910 [22766.387178] [] ? __netif_receive_skb+0x11c/0x910 [22766.387180] [] ? put_lock_stats.isra.25+0xe/0x40 [22766.387182] [] netif_receive_skb+0x23/0x1f0 [22766.387183] [] ? dev_gro_receive+0x139/0x440 [22766.387185] [] napi_skb_finish+0x70/0xa0 [22766.387187] [] napi_gro_receive+0xf5/0x130 [22766.387218] [] e1000_receive_skb+0x59/0x70 [e1000e] [22766.387242] [] e1000_clean_rx_irq+0x28b/0x460 [e1000e] [22766.387266] [] e1000e_poll+0x78/0x430 [e1000e] [22766.387268] [] net_rx_action+0x1aa/0x3d0 [22766.387270] [] ? account_system_vtime+0x10f/0x130 [22766.387273] [] __do_softirq+0xe0/0x420 [22766.387275] [] call_softirq+0x1c/0x30 [22766.387278] [] do_softirq+0xd5/0x110 [22766.387279] [] irq_exit+0xd5/0xe0 [22766.387281] [] do_IRQ+0x63/0xd0 [22766.387283] [] common_interrupt+0x6f/0x6f [22766.387283] [22766.387284] [22766.387285] [] ? retint_swapgs+0x13/0x1b [22766.387285] Code: c0 90 5d c3 66 0f 1f 44 00 00 4c 89 c8 5d c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89 5d e8 4c 89 65 f0 4c 89 6d f8 66 66 66 66 90 <0f> b7 87 98 00 00 00 48 89 fb 49 89 f5 66 c1 c0 08 66 39 46 02 [22766.387307] [22766.387307] RIP [22766.387311] [] sctp_assoc_is_match+0x19/0x90 [sctp] [22766.387311] RSP [22766.387142] ffffffffa16ab120 [22766.599537] ---[ end trace 3f6dae82e37b17f5 ]--- [22766.601221] Kernel panic - not syncing: Fatal exception in interrupt It appears from his analysis and some staring at the code that this is likely occuring because an association is getting freed while still on the sctp_assoc_hashtable. As a result, we get a gpf when traversing the hashtable while a freed node corrupts part of the list. Nominally I would think that an mibalanced refcount was responsible for this, but I can't seem to find any obvious imbalance. What I did note however was that the two places where we create an association using sctp_primitive_ASSOCIATE (__sctp_connect and sctp_sendmsg), have failure paths which free a newly created association after calling sctp_primitive_ASSOCIATE. sctp_primitive_ASSOCIATE brings us into the sctp_sf_do_prm_asoc path, which issues a SCTP_CMD_NEW_ASOC side effect, which in turn adds a new association to the aforementioned hash table. the sctp command interpreter that process side effects has not way to unwind previously processed commands, so freeing the association from the __sctp_connect or sctp_sendmsg error path would lead to a freed association remaining on this hash table. I've fixed this but modifying sctp_[un]hash_established to use hlist_del_init, which allows us to proerly use hlist_unhashed to check if the node is on a hashlist safely during a delete. That in turn alows us to safely call sctp_unhash_established in the __sctp_connect and sctp_sendmsg error paths before freeing them, regardles of what the associations state is on the hash list. I noted, while I was doing this, that the __sctp_unhash_endpoint was using hlist_unhsashed in a simmilar fashion, but never nullified any removed nodes pointers to make that function work properly, so I fixed that up in a simmilar fashion. I attempted to test this using a virtual guest running the SCTP_RR test from netperf in a loop while running the trinity fuzzer, both in a loop. I wasn't able to recreate the problem prior to this fix, nor was I able to trigger the failure after (neither of which I suppose is suprising). Given the trace above however, I think its likely that this is what we hit. Signed-off-by: Neil Horman Reported-by: davej@redhat.com CC: davej@redhat.com CC: "David S. Miller" CC: Vlad Yasevich CC: Sridhar Samudrala CC: linux-sctp@vger.kernel.org Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: Allow struct sctp_event_subscribe to grow without breaking binaries

2012-04-27T16:51:18Z

[ Upstream commit acdd5985364f8dc511a0762fab2e683f29d9d692 ] getsockopt(..., SCTP_EVENTS, ...) performs a length check and returns an error if the user provides less bytes than the size of struct sctp_event_subscribe. Struct sctp_event_subscribe needs to be extended by an u8 for every new event or notification type that is added. This obviously makes getsockopt fail for binaries that are compiled against an older versions of which do not contain all event types. This patch changes getsockopt behaviour to no longer return an error if not enough bytes are being provided by the user. Instead, it returns as much of sctp_event_subscribe as fits into the provided buffer. This leads to the new behavior that users see what they have been aware of at compile time. The setsockopt(..., SCTP_EVENTS, ...) API is already behaving like this. Signed-off-by: Thomas Graf Acked-by: Vlad Yasevich Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: fix incorrect overflow check on autoclose

2012-01-06T22:14:08Z

[ Upstream commit 2692ba61a82203404abd7dd2a027bda962861f74 ] Commit 8ffd3208 voids the previous patches f6778aab and 810c0719 for limiting the autoclose value. If userspace passes in -1 on 32-bit platform, the overflow check didn't work and autoclose would be set to 0xffffffff. This patch defines a max_autoclose (in seconds) for limiting the value and exposes it through sysctl, with the following intentions. 1) Avoid overflowing autoclose * HZ. 2) Keep the default autoclose bound consistent across 32- and 64-bit platforms (INT_MAX / HZ in this patch). 3) Keep the autoclose value consistent between setsockopt() and getsockopt() calls. Suggested-by: Vlad Yasevich Signed-off-by: Xi Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: ABORT if receive, reassmbly, or reodering queue is not empty while closing socket

2011-07-08T16:53:08Z

Trigger user ABORT if application closes a socket which has data queued on the socket receive queue or chunks waiting on the reassembly or ordering queue as this would imply data being lost which defeats the point of a graceful shutdown. This behavior is already practiced in TCP. We do not check the input queue because that would mean to parse all chunks on it to look for unacknowledged data which seems too much of an effort. Control chunks or duplicated chunks may also be in the input queue and should not be stopping a graceful shutdown. Signed-off-by: Thomas Graf Acked-by: Vlad Yasevich Signed-off-by: David S. Miller

sctp: fix missing send up SCTP_SENDER_DRY_EVENT when subscribe it

2011-07-07T11:10:26Z

We forgot to send up SCTP_SENDER_DRY_EVENT notification when user app subscribes to this event, and there is no data to be sent or retransmit. This is required by the Socket API and used by the DTLS/SCTP implementation. Reported-by: Michael Tüxen Signed-off-by: Wei Yongjun Tested-by: Robin Seggelmann Signed-off-by: David S. Miller

sctp: sctp_sendmsg: Don't test known non-null sinfo

2011-05-12T21:30:50Z

It's already known non-null above. Signed-off-by: Joe Perches Signed-off-by: David S. Miller

sctp: sctp_sendmsg: Don't initialize default_sinfo

2011-05-12T21:30:49Z

This variable only needs initialization when cmsgs.info is NULL. Use memset to ensure padding is also zeroed so kernel doesn't leak any data. Signed-off-by: Joe Perches Signed-off-by: David S. Miller