linux/net, branch mybooklive-amatus

net: sendmsg: fix NULL pointer dereference

2014-07-29T19:20:22Z

Sasha's report: > While fuzzing with trinity inside a KVM tools guest running the latest -next > kernel with the KASAN patchset, I've stumbled on the following spew: > > [ 4448.949424] ================================================================== > [ 4448.951737] AddressSanitizer: user-memory-access on address 0 > [ 4448.952988] Read of size 2 by thread T19638: > [ 4448.954510] CPU: 28 PID: 19638 Comm: trinity-c76 Not tainted 3.16.0-rc4-next-20140711-sasha-00046-g07d3099-dirty #813 > [ 4448.956823] ffff88046d86ca40 0000000000000000 ffff880082f37e78 ffff880082f37a40 > [ 4448.958233] ffffffffb6e47068 ffff880082f37a68 ffff880082f37a58 ffffffffb242708d > [ 4448.959552] 0000000000000000 ffff880082f37a88 ffffffffb24255b1 0000000000000000 > [ 4448.961266] Call Trace: > [ 4448.963158] dump_stack (lib/dump_stack.c:52) > [ 4448.964244] kasan_report_user_access (mm/kasan/report.c:184) > [ 4448.965507] __asan_load2 (mm/kasan/kasan.c:352) > [ 4448.966482] ? netlink_sendmsg (net/netlink/af_netlink.c:2339) > [ 4448.967541] netlink_sendmsg (net/netlink/af_netlink.c:2339) > [ 4448.968537] ? get_parent_ip (kernel/sched/core.c:2555) > [ 4448.970103] sock_sendmsg (net/socket.c:654) > [ 4448.971584] ? might_fault (mm/memory.c:3741) > [ 4448.972526] ? might_fault (./arch/x86/include/asm/current.h:14 mm/memory.c:3740) > [ 4448.973596] ? verify_iovec (net/core/iovec.c:64) > [ 4448.974522] ___sys_sendmsg (net/socket.c:2096) > [ 4448.975797] ? put_lock_stats.isra.13 (./arch/x86/include/asm/preempt.h:98 kernel/locking/lockdep.c:254) > [ 4448.977030] ? lock_release_holdtime (kernel/locking/lockdep.c:273) > [ 4448.978197] ? lock_release_non_nested (kernel/locking/lockdep.c:3434 (discriminator 1)) > [ 4448.979346] ? check_chain_key (kernel/locking/lockdep.c:2188) > [ 4448.980535] __sys_sendmmsg (net/socket.c:2181) > [ 4448.981592] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2600) > [ 4448.982773] ? trace_hardirqs_on (kernel/locking/lockdep.c:2607) > [ 4448.984458] ? syscall_trace_enter (arch/x86/kernel/ptrace.c:1500 (discriminator 2)) > [ 4448.985621] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2600) > [ 4448.986754] SyS_sendmmsg (net/socket.c:2201) > [ 4448.987708] tracesys (arch/x86/kernel/entry_64.S:542) > [ 4448.988929] ================================================================== This reports means that we've come to netlink_sendmsg() with msg->msg_name == NULL and msg->msg_namelen > 0. After this report there was no usual "Unable to handle kernel NULL pointer dereference" and this gave me a clue that address 0 is mapped and contains valid socket address structure in it. This bug was introduced in f3d3342602f8bcbf37d7c46641cb9bca7618eb1c (net: rework recvmsg handler msg_name and msg_namelen logic). Commit message states that: "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." But in fact this affects sendto when address 0 is mapped and contains socket address structure in it. In such case copy-in address will succeed, verify_iovec() function will successfully exit with msg->msg_namelen > 0 and msg->msg_name == NULL. This patch fixes it by setting msg_namelen to 0 if msg_name == NULL. Cc: Hannes Frederic Sowa Cc: Eric Dumazet Cc: Reported-by: Sasha Levin Signed-off-by: Andrey Ryabinin Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller

ip: make IP identifiers less predictable

2014-07-29T01:46:34Z

In "Counting Packets Sent Between Arbitrary Internet Hosts", Jeffrey and Jedidiah describe ways exploiting linux IP identifier generation to infer whether two machines are exchanging packets. With commit 73f156a6e8c1 ("inetpeer: get rid of ip_id_count"), we changed IP id generation, but this does not really prevent this side-channel technique. This patch adds a random amount of perturbation so that IP identifiers for a given destination [1] are no longer monotonically increasing after an idle period. Note that prandom_u32_max(1) returns 0, so if generator is used at most once per jiffy, this patch inserts no hole in the ID suite and do not increase collision probability. This is jiffies based, so in the worst case (HZ=1000), the id can rollover after ~65 seconds of idle time, which should be fine. We also change the hash used in __ip_select_ident() to not only hash on daddr, but also saddr and protocol, so that ICMP probes can not be used to infer information for other protocols. For IPv6, adds saddr into the hash as well, but not nexthdr. If I ping the patched target, we can see ID are now hard to predict. 21:57:11.008086 IP (...) A > target: ICMP echo request, seq 1, length 64 21:57:11.010752 IP (... id 2081 ...) target > A: ICMP echo reply, seq 1, length 64 21:57:12.013133 IP (...) A > target: ICMP echo request, seq 2, length 64 21:57:12.015737 IP (... id 3039 ...) target > A: ICMP echo reply, seq 2, length 64 21:57:13.016580 IP (...) A > target: ICMP echo request, seq 3, length 64 21:57:13.019251 IP (... id 3437 ...) target > A: ICMP echo reply, seq 3, length 64 [1] TCP sessions uses a per flow ID generator not changed by this patch. Signed-off-by: Eric Dumazet Reported-by: Jeffrey Knockel Reported-by: Jedidiah R. Crandall Cc: Willy Tarreau Cc: Hannes Frederic Sowa Signed-off-by: David S. Miller

neighbour : fix ndm_type type error issue

2014-07-29T00:52:17Z

ndm_type means L3 address type, in neighbour proxy and vxlan, it's RTN_UNICAST. NDA_DST is for netlink TLV type, hence it's not right value in this context. Signed-off-by: Jun Zhao Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller

Merge tag 'master-2014-07-23' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless

2014-07-25T06:22:15Z

John W. Linville says: ==================== pull request: wireless 2014-07-24 Please pull this batch of fixes intended for the 3.16 stream... For the mac80211 fixes, Johannes says: "I have two fixes: one for tracing that fixes a long-standing NULL pointer dereference, and one for a mac80211 issue that causes iwlmvm to send invalid frames during authentication/association." and, "One more fix - for a bug in the newly introduced code that obtains rate control information for stations." For the iwlwifi fixes, Emmanuel says: "It includes a merge damage fix. This region has been changed in -next and -fixes quite a few times and apparently, I failed to handle it properly, so here the fix. Along with that I have a fix from Eliad to properly handle overlapping BSS in AP mode." On top of that, Felix provides and ath9k fix for Tx stalls that happen after an aggregation session failure. Please let me know if there are problems! There are some changes here that will cause merge conflicts in -next. Once you merge this I can pull it into wireless-next and resolve those issues. ==================== Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf

2014-07-25T01:00:05Z

Pablo Neira Ayuso says: ==================== Via Simon Horman, I received the following one-liner for your net tree: 1) Fix crash when exiting from netns that uses IPVS and conntrack, from Julian Anastasov via Simon Horman. ==================== Signed-off-by: David S. Miller

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

2014-07-24T04:56:36Z

Steffen Klassert says: ==================== pull request (net): ipsec 2014-07-23 Just two fixes this time, both are stable candidates. 1) Fix the dst_entry refcount on socket policy usage. 2) Fix a wrong SPI check that prevents AH SAs from getting installed, dependent on the SPI. From Tobias Brunner. ==================== Signed-off-by: David S. Miller

Merge branch 'for-john' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211

2014-07-23T17:01:14Z

net: sctp: inherit auth_capable on INIT collisions

2014-07-23T02:56:58Z

Jason reported an oops caused by SCTP on his ARM machine with SCTP authentication enabled: Internal error: Oops: 17 [#1] ARM CPU: 0 PID: 104 Comm: sctp-test Not tainted 3.13.0-68744-g3632f30c9b20-dirty #1 task: c6eefa40 ti: c6f52000 task.ti: c6f52000 PC is at sctp_auth_calculate_hmac+0xc4/0x10c LR is at sg_init_table+0x20/0x38 pc : [] lr : [] psr: 40000013 sp : c6f538e8 ip : 00000000 fp : c6f53924 r10: c6f50d80 r9 : 00000000 r8 : 00010000 r7 : 00000000 r6 : c7be4000 r5 : 00000000 r4 : c6f56254 r3 : c00c8170 r2 : 00000001 r1 : 00000008 r0 : c6f1e660 Flags: nZcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 0005397f Table: 06f28000 DAC: 00000015 Process sctp-test (pid: 104, stack limit = 0xc6f521c0) Stack: (0xc6f538e8 to 0xc6f54000) [...] Backtrace: [] (sctp_auth_calculate_hmac+0x0/0x10c) from [] (sctp_packet_transmit+0x33c/0x5c8) [] (sctp_packet_transmit+0x0/0x5c8) from [] (sctp_outq_flush+0x7fc/0x844) [] (sctp_outq_flush+0x0/0x844) from [] (sctp_outq_uncork+0x24/0x28) [] (sctp_outq_uncork+0x0/0x28) from [] (sctp_side_effects+0x1134/0x1220) [] (sctp_side_effects+0x0/0x1220) from [] (sctp_do_sm+0xac/0xd4) [] (sctp_do_sm+0x0/0xd4) from [] (sctp_assoc_bh_rcv+0x118/0x160) [] (sctp_assoc_bh_rcv+0x0/0x160) from [] (sctp_inq_push+0x6c/0x74) [] (sctp_inq_push+0x0/0x74) from [] (sctp_rcv+0x7d8/0x888) While we already had various kind of bugs in that area ec0223ec48a9 ("net: sctp: fix sctp_sf_do_5_1D_ce to verify if we/peer is AUTH capable") and b14878ccb7fa ("net: sctp: cache auth_enable per endpoint"), this one is a bit of a different kind. Giving a bit more background on why SCTP authentication is needed can be found in RFC4895: SCTP uses 32-bit verification tags to protect itself against blind attackers. These values are not changed during the lifetime of an SCTP association. Looking at new SCTP extensions, there is the need to have a method of proving that an SCTP chunk(s) was really sent by the original peer that started the association and not by a malicious attacker. To cause this bug, we're triggering an INIT collision between peers; normal SCTP handshake where both sides intent to authenticate packets contains RANDOM; CHUNKS; HMAC-ALGO parameters that are being negotiated among peers: ---------- INIT[RANDOM; CHUNKS; HMAC-ALGO] ----------> <------- INIT-ACK[RANDOM; CHUNKS; HMAC-ALGO] --------- -------------------- COOKIE-ECHO --------------------> <-------------------- COOKIE-ACK --------------------- RFC4895 says that each endpoint therefore knows its own random number and the peer's random number *after* the association has been established. The local and peer's random number along with the shared key are then part of the secret used for calculating the HMAC in the AUTH chunk. Now, in our scenario, we have 2 threads with 1 non-blocking SEQ_PACKET socket each, setting up common shared SCTP_AUTH_KEY and SCTP_AUTH_ACTIVE_KEY properly, and each of them calling sctp_bindx(3), listen(2) and connect(2) against each other, thus the handshake looks similar to this, e.g.: ---------- INIT[RANDOM; CHUNKS; HMAC-ALGO] ----------> <------- INIT-ACK[RANDOM; CHUNKS; HMAC-ALGO] --------- <--------- INIT[RANDOM; CHUNKS; HMAC-ALGO] ----------- -------- INIT-ACK[RANDOM; CHUNKS; HMAC-ALGO] --------> ... Since such collisions can also happen with verification tags, the RFC4895 for AUTH rather vaguely says under section 6.1: In case of INIT collision, the rules governing the handling of this Random Number follow the same pattern as those for the Verification Tag, as explained in Section 5.2.4 of RFC 2960 [5]. Therefore, each endpoint knows its own Random Number and the peer's Random Number after the association has been established. In RFC2960, section 5.2.4, we're eventually hitting Action B: B) In this case, both sides may be attempting to start an association at about the same time but the peer endpoint started its INIT after responding to the local endpoint's INIT. Thus it may have picked a new Verification Tag not being aware of the previous Tag it had sent this endpoint. The endpoint should stay in or enter the ESTABLISHED state but it MUST update its peer's Verification Tag from the State Cookie, stop any init or cookie timers that may running and send a COOKIE ACK. In other words, the handling of the Random parameter is the same as behavior for the Verification Tag as described in Action B of section 5.2.4. Looking at the code, we exactly hit the sctp_sf_do_dupcook_b() case which triggers an SCTP_CMD_UPDATE_ASSOC command to the side effect interpreter, and in fact it properly copies over peer_{random, hmacs, chunks} parameters from the newly created association to update the existing one. Also, the old asoc_shared_key is being released and based on the new params, sctp_auth_asoc_init_active_key() updated. However, the issue observed in this case is that the previous asoc->peer.auth_capable was 0, and has *not* been updated, so that instead of creating a new secret, we're doing an early return from the function sctp_auth_asoc_init_active_key() leaving asoc->asoc_shared_key as NULL. However, we now have to authenticate chunks from the updated chunk list (e.g. COOKIE-ACK). That in fact causes the server side when responding with ... <------------------ AUTH; COOKIE-ACK ----------------- ... to trigger a NULL pointer dereference, since in sctp_packet_transmit(), it discovers that an AUTH chunk is being queued for xmit, and thus it calls sctp_auth_calculate_hmac(). Since the asoc->active_key_id is still inherited from the endpoint, and the same as encoded into the chunk, it uses asoc->asoc_shared_key, which is still NULL, as an asoc_key and dereferences it in ... crypto_hash_setkey(desc.tfm, &asoc_key->data[0], asoc_key->len) ... causing an oops. All this happens because sctp_make_cookie_ack() called with the *new* association has the peer.auth_capable=1 and therefore marks the chunk with auth=1 after checking sctp_auth_send_cid(), but it is *actually* sent later on over the then *updated* association's transport that didn't initialize its shared key due to peer.auth_capable=0. Since control chunks in that case are not sent by the temporary association which are scheduled for deletion, they are issued for xmit via SCTP_CMD_REPLY in the interpreter with the context of the *updated* association. peer.auth_capable was 0 in the updated association (which went from COOKIE_WAIT into ESTABLISHED state), since all previous processing that performed sctp_process_init() was being done on temporary associations, that we eventually throw away each time. The correct fix is to update to the new peer.auth_capable value as well in the collision case via sctp_assoc_update(), so that in case the collision migrated from 0 -> 1, sctp_auth_asoc_init_active_key() can properly recalculate the secret. This therefore fixes the observed server panic. Fixes: 730fc3d05cd4 ("[SCTP]: Implete SCTP-AUTH parameter processing") Reported-by: Jason Gunthorpe Signed-off-by: Daniel Borkmann Tested-by: Jason Gunthorpe Cc: Vlad Yasevich Acked-by: Vlad Yasevich Signed-off-by: David S. Miller

mac80211: fix crash on getting sta info with uninitialized rate control

2014-07-22T20:17:17Z

If the expected throughput is queried before rate control has been initialized, the minstrel op for it will crash while trying to access the rate table. Check for WLAN_STA_RATE_CONTROL before attempting to use the rate control op. Reported-by: Jean-Pierre Tosoni Signed-off-by: Felix Fietkau Signed-off-by: Johannes Berg

Merge tag 'batman-adv-fix-for-davem' of git://git.open-mesh.org/linux-merge

2014-07-22T03:19:09Z

Antonio Quartulli says: ==================== pull request [net]: batman-adv 20140721 here you have two fixes that we have been testing for quite some time (this is why they arrived a bit late in the rc cycle). Patch 1) ensures that BLA packets get dropped and not forwarded to the mesh even if they reach batman-adv within QinQ frames. Forwarding them into the mesh means messing up with the TT database of other nodes which can generate all kind of unexpected behaviours during route computation. Patch 2) avoids a couple of race conditions triggered upon fast VLAN deletion-addition. Such race conditions are pretty dangerous because they not only create inconsistencies in the TT database of the nodes in the network, but such scenario is also unrecoverable (unless nodes are rebooted). ==================== Signed-off-by: David S. Miller