linux.git, branch v3.18.46

Linux 3.18.46

2016-12-24T16:10:18+00:00

Signed-off-by: Sasha Levin

packet: fix race condition in packet_set_ring

2016-12-23T15:39:29+00:00

[ Upstream commit 84ac7260236a49c79eede91617700174c2c19b0c ]

When packet_set_ring creates a ring buffer it will initialize a
struct timer_list if the packet version is TPACKET_V3. This value
can then be raced by a different thread calling setsockopt to
set the version to TPACKET_V1 before packet_set_ring has finished.

This leads to a use-after-free on a function pointer in the
struct timer_list when the socket is closed as the previously
initialized timer will not be deleted.

The bug is fixed by taking lock_sock(sk) in packet_setsockopt when
changing the packet version while also taking the lock at the start
of packet_set_ring.

Fixes: f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation.")
Signed-off-by: Philip Pettersson 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

Bluetooth: Fix potential NULL dereference in RFCOMM bind callback

2016-12-23T15:39:29+00:00

[ Upstream commit 951b6a0717db97ce420547222647bcc40bf1eacd ]

addr can be NULL and it should not be dereferenced before NULL checking.

Signed-off-by: Jaganath Kanakkassery 
Signed-off-by: Marcel Holtmann 
Signed-off-by: Sasha Levin

scsi: arcmsr: Buffer overflow in arcmsr_iop_message_xfer()

2016-12-23T15:39:29+00:00

[ Upstream commit 7bc2b55a5c030685b399bb65b6baa9ccc3d1f167 ]

We need to put an upper bound on "user_len" so the memcpy() doesn't
overflow.

Cc: 
Reported-by: Marco Grassi 
Signed-off-by: Dan Carpenter 
Reviewed-by: Tomas Henzl 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

nfsd: Disable NFSv2 timestamp workaround for NFSv3+

2016-12-23T14:42:23+00:00

[ Upstream commit cc265089ce1b176dde963c74b53593446ee7f99a ]

NFSv2 can set the atime and/or mtime of a file to specific timestamps but not
to the server's current time.  To implement the equivalent of utimes("file",
NULL), it uses a heuristic.

NFSv3 and later do support setting the atime and/or mtime to the server's
current time directly.  The NFSv2 heuristic is still enabled, and causes
timestamps to be set wrong sometimes.

Fix this by moving the heuristic into the NFSv2 specific code.  We can leave it
out of the create code path: the owner can always set timestamps arbitrarily,
and the workaround would never trigger.

Signed-off-by: Andreas Gruenbacher 
Reviewed-by: Christoph Hellwig 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Sasha Levin

fuse: Propagate dentry down to inode_change_ok()

2016-12-23T14:42:19+00:00

[ Upstream commit 62490330769c1ce5dcba3f1f3e8f4005e9b797e6 ]

To avoid clearing of capabilities or security related extended
attributes too early, inode_change_ok() will need to take dentry instead
of inode. Propagate it down to fuse_do_setattr().

Acked-by: Miklos Szeredi 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jan Kara 
Signed-off-by: Sasha Levin

tcp: fix use after free in tcp_xmit_retransmit_queue()

2016-12-23T14:41:56+00:00

[ Upstream commit bb1fceca22492109be12640d49f5ea5a544c6bb4 ]

When tcp_sendmsg() allocates a fresh and empty skb, it puts it at the
tail of the write queue using tcp_add_write_queue_tail()

Then it attempts to copy user data into this fresh skb.

If the copy fails, we undo the work and remove the fresh skb.

Unfortunately, this undo lacks the change done to tp->highest_sack and
we can leave a dangling pointer (to a freed skb)

Later, tcp_xmit_retransmit_queue() can dereference this pointer and
access freed memory. For regular kernels where memory is not unmapped,
this might cause SACK bugs because tcp_highest_sack_seq() is buggy,
returning garbage instead of tp->snd_nxt, but with various debug
features like CONFIG_DEBUG_PAGEALLOC, this can crash the kernel.

This bug was found by Marco Grassi thanks to syzkaller.

Fixes: 6859d49475d4 ("[TCP]: Abstract tp->highest_sack accessing & point to next skb")
Reported-by: Marco Grassi 
Signed-off-by: Eric Dumazet 
Cc: Ilpo Järvinen 
Cc: Yuchung Cheng 
Cc: Neal Cardwell 
Acked-by: Neal Cardwell 
Reviewed-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

x86/kexec: add -fno-PIE

2016-12-23T14:41:46+00:00

[ Upstream commit 90944e40ba1838de4b2a9290cf273f9d76bd3bdd ]

If the gcc is configured to do -fPIE by default then the build aborts
later with:
| Unsupported relocation type: unknown type rel type name (29)

Tagging it stable so it is possible to compile recent stable kernels as
well.

Cc: stable@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Michal Marek 
Signed-off-by: Sasha Levin

scripts/has-stack-protector: add -fno-PIE

2016-12-23T14:41:40+00:00

[ Upstream commit 82031ea29e454b574bc6f49a33683a693ca5d907 ]

Adding -no-PIE to the fstack protector check. -no-PIE was introduced
before -fstack-protector so there is no need for a runtime check.

Without it the build stops:
|Cannot use CONFIG_CC_STACKPROTECTOR_STRONG: -fstack-protector-strong available but compiler is broken

due to -mcmodel=kernel + -fPIE if -fPIE is enabled by default.

Tagging it stable so it is possible to compile recent stable kernels as
well.

Cc: stable@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Michal Marek 
Signed-off-by: Sasha Levin

x86/init: Fix cr4_init_shadow() on CR4-less machines

2016-12-23T14:41:34+00:00

[ Upstream commit e1bfc11c5a6f40222a698a818dc269113245820e ]

cr4_init_shadow() will panic on 486-like machines without CR4.  Fix
it using __read_cr4_safe().

Reported-by: david@saggiorato.net
Signed-off-by: Andy Lutomirski 
Reviewed-by: Borislav Petkov 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: stable@vger.kernel.org
Fixes: 1e02ce4cccdc ("x86: Store a per-cpu shadow copy of CR4")
Link: http://lkml.kernel.org/r/43a20f81fb504013bf613913dc25574b45336a61.1475091074.git.luto@kernel.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin