linux/net/netlink, branch v4.9

netlink: Do not schedule work from sk_destruct

2016-12-06T00:43:42Z

It is wrong to schedule a work from sk_destruct using the socket as the memory reserve because the socket will be freed immediately after the return from sk_destruct. Instead we should do the deferral prior to sk_free. This patch does just that. Fixes: 707693c8a498 ("netlink: Call cb->done from a worker thread") Signed-off-by: Herbert Xu Tested-by: Andrey Konovalov Signed-off-by: David S. Miller

netlink: Call cb->done from a worker thread

2016-11-30T00:48:38Z

The cb->done interface expects to be called in process context. This was broken by the netlink RCU conversion. This patch fixes it by adding a worker struct to make the cb->done call where necessary. Fixes: 21e4902aea80 ("netlink: Lockless lookup with RCU grace...") Reported-by: Subash Abhinov Kasiviswanathan Signed-off-by: Herbert Xu Acked-by: Cong Wang Signed-off-by: David S. Miller

genetlink: fix a memory leak on error path

2016-11-03T20:52:29Z

In __genl_register_family(), when genl_validate_assign_mc_groups() fails, we forget to free the memory we possibly allocate for family->attrbuf. Note, some callers call genl_unregister_family() to clean up on error path, it doesn't work because the family is inserted to the global list in the nearly last step. Cc: Jakub Kicinski Cc: Johannes Berg Signed-off-by: Cong Wang Signed-off-by: David S. Miller

netlink: netlink_diag_dump() runs without locks

2016-11-03T20:16:51Z

A recent commit removed locking from netlink_diag_dump() but forgot one error case. ===================================== [ BUG: bad unlock balance detected! ] 4.9.0-rc3+ #336 Not tainted ------------------------------------- syz-executor/4018 is trying to release lock ([ 36.220068] nl_table_lock ) at: [] netlink_diag_dump+0x1a3/0x250 net/netlink/diag.c:182 but there are no more locks to release! other info that might help us debug this: 3 locks held by syz-executor/4018: #0: [ 36.220068] ( sock_diag_mutex[ 36.220068] ){+.+.+.} , at: [ 36.220068] [] sock_diag_rcv+0x1b/0x40 #1: [ 36.220068] ( sock_diag_table_mutex[ 36.220068] ){+.+.+.} , at: [ 36.220068] [] sock_diag_rcv_msg+0x140/0x3a0 #2: [ 36.220068] ( nlk->cb_mutex[ 36.220068] ){+.+.+.} , at: [ 36.220068] [] netlink_dump+0x50/0xac0 stack backtrace: CPU: 1 PID: 4018 Comm: syz-executor Not tainted 4.9.0-rc3+ #336 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 ffff8800645df688 ffffffff81b46934 ffffffff84eb3e78 ffff88006ad85800 ffffffff82dc8683 ffffffff84eb3e78 ffff8800645df6b8 ffffffff812043ca dffffc0000000000 ffff88006ad85ff8 ffff88006ad85fd0 00000000ffffffff Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [] dump_stack+0xb3/0x10f lib/dump_stack.c:51 [] print_unlock_imbalance_bug+0x17a/0x1a0 kernel/locking/lockdep.c:3388 [< inline >] __lock_release kernel/locking/lockdep.c:3512 [] lock_release+0x8e8/0xc60 kernel/locking/lockdep.c:3765 [< inline >] __raw_read_unlock ./include/linux/rwlock_api_smp.h:225 [] _raw_read_unlock+0x1a/0x30 kernel/locking/spinlock.c:255 [] netlink_diag_dump+0x1a3/0x250 net/netlink/diag.c:182 [] netlink_dump+0x397/0xac0 net/netlink/af_netlink.c:2110 Fixes: ad202074320c ("netlink: Use rhashtable walk interface in diag dump") Signed-off-by: Eric Dumazet Reported-by: Andrey Konovalov Tested-by: Andrey Konovalov Signed-off-by: David S. Miller

netlink: do not enter direct reclaim from netlink_dump()

2016-10-07T00:53:13Z

Since linux-3.15, netlink_dump() can use up to 16384 bytes skb allocations. Due to struct skb_shared_info ~320 bytes overhead, we end up using order-3 (on x86) page allocations, that might trigger direct reclaim and add stress. The intent was really to attempt a large allocation but immediately fallback to a smaller one (order-1 on x86) in case of memory stress. On recent kernels (linux-4.4), we can remove __GFP_DIRECT_RECLAIM to meet the goal. Old kernels would need to remove __GFP_WAIT While we are at it, since we do an order-3 allocation, allow to use all the allocated bytes instead of 16384 to reduce syscalls during large dumps. iproute2 already uses 32KB recvmsg() buffer sizes. Alexei provided an initial patch downsizing to SKB_WITH_OVERHEAD(16384) Fixes: 9063e21fb026 ("netlink: autosize skb lengthes") Signed-off-by: Eric Dumazet Reported-by: Alexei Starovoitov Cc: Greg Thelen Reviewed-by: Greg Rose Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller

netlink: don't forget to release a rhashtable_iter structure

2016-09-08T00:29:38Z

This bug was detected by kmemleak: unreferenced object 0xffff8804269cc3c0 (size 64): comm "criu", pid 1042, jiffies 4294907360 (age 13.713s) hex dump (first 32 bytes): a0 32 cc 2c 04 88 ff ff 00 00 00 00 00 00 00 00 .2.,............ 00 01 00 00 00 00 ad de 00 02 00 00 00 00 ad de ................ backtrace: [] kmemleak_alloc+0x4a/0xa0 [] kmem_cache_alloc_trace+0x10f/0x280 [] __netlink_diag_dump+0x26c/0x290 [netlink_diag] v2: don't remove a reference on a rhashtable_iter structure to release it from netlink_diag_dump_done Cc: Herbert Xu Fixes: ad202074320c ("netlink: Use rhashtable walk interface in diag dump") Signed-off-by: Andrei Vagin Acked-by: Herbert Xu Signed-off-by: David S. Miller

net: make genetlink ctrl ops const

2016-09-01T21:09:00Z

Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller

netlink: Use rhashtable walk interface in diag dump

2016-08-19T21:40:25Z

This patch converts the diag dumping code to use the rhashtable walk code instead of going through rhashtable by hand. The lock nl_table_lock is now only taken while we process the multicast list as it's not needed for the rhashtable walk. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller

net/netlink/af_netlink.h: Remove unused structure.

2016-06-10T05:26:24Z

Signed-off-by: Fabien Siron Signed-off-by: David S. Miller

netlink: Fix dump skb leak/double free

2016-05-17T02:05:15Z

When we free cb->skb after a dump, we do it after releasing the lock. This means that a new dump could have started in the time being and we'll end up freeing their skb instead of ours. This patch saves the skb and module before we unlock so we free the right memory. Fixes: 16b304f3404f ("netlink: Eliminate kmalloc in netlink dump operation.") Reported-by: Baozeng Ding Signed-off-by: Herbert Xu Acked-by: Cong Wang Signed-off-by: David S. Miller