kernel/include/net/sock.h, branch linux-3.15.y

net: fix sparse warning in sk_dst_set()

2014-07-28T15:08:23Z

[ Upstream commit 5925a0555bdaf0b396a84318cbc21ba085f6c0d3 ] sk_dst_cache has __rcu annotation, so we need a cast to avoid following sparse error : include/net/sock.h:1774:19: warning: incorrect type in initializer (different address spaces) include/net/sock.h:1774:19: expected struct dst_entry [noderef] *__ret include/net/sock.h:1774:19: got struct dst_entry *dst Signed-off-by: Eric Dumazet Reported-by: kbuild test robot Fixes: 7f502361531e ("ipv4: irq safe sk_dst_[re]set() and ipv4_sk_update_pmtu() fix") Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: irq safe sk_dst_[re]set() and ipv4_sk_update_pmtu() fix

2014-07-28T15:08:23Z

[ Upstream commit 7f502361531e9eecb396cf99bdc9e9a59f7ebd7f ] We have two different ways to handle changes to sk->sk_dst First way (used by TCP) assumes socket lock is owned by caller, and use no extra lock : __sk_dst_set() & __sk_dst_reset() Another way (used by UDP) uses sk_dst_lock because socket lock is not always taken. Note that sk_dst_lock is not softirq safe. These ways are not inter changeable for a given socket type. ipv4_sk_update_pmtu(), added in linux-3.8, added a race, as it used the socket lock as synchronization, but users might be UDP sockets. Instead of converting sk_dst_lock to a softirq safe version, use xchg() as we did for sk_rx_dst in commit e47eb5dfb296b ("udp: ipv4: do not use sk_dst_lock from softirq context") In a follow up patch, we probably can remove sk_dst_lock, as it is only used in IPv6. Signed-off-by: Eric Dumazet Cc: Steffen Klassert Fixes: 9cb3a50c5f63e ("ipv4: Invalidate the socket cached route on pmtu events if possible") Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: fix dst race in sk_dst_get()

2014-07-28T15:08:23Z

[ Upstream commit f88649721268999bdff09777847080a52004f691 ] When IP route cache had been removed in linux-3.6, we broke assumption that dst entries were all freed after rcu grace period. DST_NOCACHE dst were supposed to be freed from dst_release(). But it appears we want to keep such dst around, either in UDP sockets or tunnels. In sk_dst_get() we need to make sure dst refcount is not 0 before incrementing it, or else we might end up freeing a dst twice. DST_NOCACHE set on a dst does not mean this dst can not be attached to a socket or a tunnel. Then, before actual freeing, we need to observe a rcu grace period to make sure all other cpus can catch the fact the dst is no longer usable. Signed-off-by: Eric Dumazet Reported-by: Dormando Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: Add variants of capable for use on on sockets

2014-04-24T17:44:53Z

sk_net_capable - The common case, operations that are safe in a network namespace. sk_capable - Operations that are not known to be safe in a network namespace sk_ns_capable - The general case for special cases. Signed-off-by: "Eric W. Biederman" Signed-off-by: David S. Miller

net: Fix use after free by removing length arg from sk_data_ready callbacks.

2014-04-11T20:15:36Z

Several spots in the kernel perform a sequence like: skb_queue_tail(&sk->s_receive_queue, skb); sk->sk_data_ready(sk, skb->len); But at the moment we place the SKB onto the socket receive queue it can be consumed and freed up. So this skb->len access is potentially to freed up memory. Furthermore, the skb->len can be modified by the consumer so it is possible that the value isn't accurate. And finally, no actual implementation of this callback actually uses the length argument. And since nobody actually cared about it's value, lots of call sites pass arbitrary values in such as '0' and even '1'. So just remove the length argument from the callback, that way there is no confusion whatsoever and all of these use-after-free cases get fixed as a side effect. Based upon a patch by Eric Dumazet and his suggestion to audit this issue tree-wide. Signed-off-by: David S. Miller

net: filter: move filter accounting to filter core

2014-03-31T04:45:09Z

This patch basically does two things, i) removes the extern keyword from the include/linux/filter.h file to be more consistent with the rest of Joe's changes, and ii) moves filter accounting into the filter core framework. Filter accounting mainly done through sk_filter_{un,}charge() take care of the case when sockets are being cloned through sk_clone_lock() so that removal of the filter on one socket won't result in eviction as it's still referenced by the other. These functions actually belong to net/core/filter.c and not include/net/sock.h as we want to keep all that in a central place. It's also not in fast-path so uninlining them is fine and even allows us to get rd of sk_filter_release_rcu()'s EXPORT_SYMBOL and a forward declaration. Joint work with Alexei Starovoitov. Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov Cc: Pavel Emelyanov Signed-off-by: David S. Miller

net: Rename skb->rxhash to skb->hash

2014-03-26T19:58:20Z

The packet hash can be considered a property of the packet, not just on RX path. This patch changes name of rxhash and l4_rxhash skbuff fields to be hash and l4_hash respectively. This includes changing uses of the field in the code which don't call the access functions. Signed-off-by: Tom Herbert Signed-off-by: Eric Dumazet Cc: Mahesh Bandewar Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2014-03-15T02:31:55Z

Conflicts: drivers/net/usb/r8152.c drivers/net/xen-netback/netback.c Both the r8152 and netback conflicts were simple overlapping changes. Signed-off-by: David S. Miller

tcp: tcp_release_cb() should release socket ownership

2014-03-11T20:45:59Z

Lars Persson reported following deadlock : -000 |M:0x0:0x802B6AF8(asm) <-- arch_spin_lock -001 |tcp_v4_rcv(skb = 0x8BD527A0) <-- sk = 0x8BE6B2A0 -002 |ip_local_deliver_finish(skb = 0x8BD527A0) -003 |__netif_receive_skb_core(skb = 0x8BD527A0, ?) -004 |netif_receive_skb(skb = 0x8BD527A0) -005 |elk_poll(napi = 0x8C770500, budget = 64) -006 |net_rx_action(?) -007 |__do_softirq() -008 |do_softirq() -009 |local_bh_enable() -010 |tcp_rcv_established(sk = 0x8BE6B2A0, skb = 0x87D3A9E0, th = 0x814EBE14, ?) -011 |tcp_v4_do_rcv(sk = 0x8BE6B2A0, skb = 0x87D3A9E0) -012 |tcp_delack_timer_handler(sk = 0x8BE6B2A0) -013 |tcp_release_cb(sk = 0x8BE6B2A0) -014 |release_sock(sk = 0x8BE6B2A0) -015 |tcp_sendmsg(?, sk = 0x8BE6B2A0, ?, ?) -016 |sock_sendmsg(sock = 0x8518C4C0, msg = 0x87D8DAA8, size = 4096) -017 |kernel_sendmsg(?, ?, ?, ?, size = 4096) -018 |smb_send_kvec() -019 |smb_send_rqst(server = 0x87C4D400, rqst = 0x87D8DBA0) -020 |cifs_call_async() -021 |cifs_async_writev(wdata = 0x87FD6580) -022 |cifs_writepages(mapping = 0x852096E4, wbc = 0x87D8DC88) -023 |__writeback_single_inode(inode = 0x852095D0, wbc = 0x87D8DC88) -024 |writeback_sb_inodes(sb = 0x87D6D800, wb = 0x87E4A9C0, work = 0x87D8DD88) -025 |__writeback_inodes_wb(wb = 0x87E4A9C0, work = 0x87D8DD88) -026 |wb_writeback(wb = 0x87E4A9C0, work = 0x87D8DD88) -027 |wb_do_writeback(wb = 0x87E4A9C0, force_wait = 0) -028 |bdi_writeback_workfn(work = 0x87E4A9CC) -029 |process_one_work(worker = 0x8B045880, work = 0x87E4A9CC) -030 |worker_thread(__worker = 0x8B045880) -031 |kthread(_create = 0x87CADD90) -032 |ret_from_kernel_thread(asm) Bug occurs because __tcp_checksum_complete_user() enables BH, assuming it is running from softirq context. Lars trace involved a NIC without RX checksum support but other points are problematic as well, like the prequeue stuff. Problem is triggered by a timer, that found socket being owned by user. tcp_release_cb() should call tcp_write_timer_handler() or tcp_delack_timer_handler() in the appropriate context : BH disabled and socket lock held, but 'owned' field cleared, as if they were running from timer handlers. Fixes: 6f458dfb4092 ("tcp: improve latencies of timer triggered events") Reported-by: Lars Persson Tested-by: Lars Persson Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: add a pre-check of net_ns in sk_change_net()

2014-03-10T20:29:48Z

We do not need to switch the net_ns if the target net_ns the same as the current one, so here we add a pre-check of net_ns to avoid this as David suggested. Signed-off-by: Gu Zheng Signed-off-by: David S. Miller