linux-stable.git/Documentation, branch v3.12.64

scsi: fix race between simultaneous decrements of ->host_failed

2016-08-19T07:50:51+00:00

commit 72d8c36ec364c82bf1bf0c64dfa1041cfaf139f7 upstream.

sas_ata_strategy_handler() adds the works of the ata error handler to
system_unbound_wq. This workqueue asynchronously runs work items, so the
ata error handler will be performed concurrently on different CPUs. In
this case, ->host_failed will be decreased simultaneously in
scsi_eh_finish_cmd() on different CPUs, and become abnormal.

It will lead to permanently inequality between ->host_failed and
->host_busy, and scsi error handler thread won't start running. IO
errors after that won't be handled.

Since all scmds must have been handled in the strategy handler, just
remove the decrement in scsi_eh_finish_cmd() and zero ->host_busy after
the strategy handler to fix this race.

Fixes: 50824d6c5657 ("[SCSI] libsas: async ata-eh")
Signed-off-by: Wei Fang 
Reviewed-by: James Bottomley 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Jiri Slaby

pipe: limit the per-user amount of pages allocated in pipes

2016-04-21T11:11:54+00:00

commit 759c01142a5d0f364a462346168a56de28a80f52 upstream.

On no-so-small systems, it is possible for a single process to cause an
OOM condition by filling large pipes with data that are never read. A
typical process filling 4000 pipes with 1 MB of data will use 4 GB of
memory. On small systems it may be tricky to set the pipe max size to
prevent this from happening.

This patch makes it possible to enforce a per-user soft limit above
which new pipes will be limited to a single page, effectively limiting
them to 4 kB each, as well as a hard limit above which no new pipes may
be created for this user. This has the effect of protecting the system
against memory abuse without hurting other users, and still allowing
pipes to work correctly though with less data at once.

The limit are controlled by two new sysctls : pipe-user-pages-soft, and
pipe-user-pages-hard. Both may be disabled by setting them to zero. The
default soft limit allows the default number of FDs per process (1024)
to create pipes of the default size (64kB), thus reaching a limit of 64MB
before starting to create only smaller pipes. With 256 processes limited
to 1024 FDs each, this results in 1024*64kB + (256*1024 - 1024) * 4kB =
1084 MB of memory allocated for a user. The hard limit is disabled by
default to avoid breaking existing applications that make intensive use
of pipes (eg: for splicing).

Reported-by: socketpair@gmail.com
Reported-by: Tetsuo Handa 
Mitigates: CVE-2013-4312 (Linux 2.0+)
Suggested-by: Linus Torvalds 
Signed-off-by: Willy Tarreau 
Signed-off-by: Al Viro 
Signed-off-by: Jiri Slaby

efi: Make efivarfs entries immutable by default

2016-03-14T22:10:35+00:00

commit ed8b0de5a33d2a2557dce7f9429dca8cb5bc5879 upstream.

"rm -rf" is bricking some peoples' laptops because of variables being
used to store non-reinitializable firmware driver data that's required
to POST the hardware.

These are 100% bugs, and they need to be fixed, but in the mean time it
shouldn't be easy to *accidentally* brick machines.

We have to have delete working, and picking which variables do and don't
work for deletion is quite intractable, so instead make everything
immutable by default (except for a whitelist), and make tools that
aren't quite so broad-spectrum unset the immutable flag.

Signed-off-by: Peter Jones 
Tested-by: Lee, Chun-Yi 
Acked-by: Matthew Garrett 
Signed-off-by: Matt Fleming 
Signed-off-by: Jiri Slaby

net/ipv6: add sysctl option accept_ra_min_hop_limit

2016-03-02T15:29:06+00:00

[ Upstream commit 8013d1d7eafb0589ca766db6b74026f76b7f5cb4 ]

Commit 6fd99094de2b ("ipv6: Don't reduce hop limit for an interface")
disabled accept hop limit from RA if it is smaller than the current hop
limit for security stuff. But this behavior kind of break the RFC definition.

RFC 4861, 6.3.4.  Processing Received Router Advertisements
   A Router Advertisement field (e.g., Cur Hop Limit, Reachable Time,
   and Retrans Timer) may contain a value denoting that it is
   unspecified.  In such cases, the parameter should be ignored and the
   host should continue using whatever value it is already using.

   If the received Cur Hop Limit value is non-zero, the host SHOULD set
   its CurHopLimit variable to the received value.

So add sysctl option accept_ra_min_hop_limit to let user choose the minimum
hop limit value they can accept from RA. And set default to 1 to meet RFC
standards.

Signed-off-by: Hangbin Liu 
Acked-by: YOSHIFUJI Hideaki 
Signed-off-by: David S. Miller 
Signed-off-by: Jiri Slaby

i2c: i801: add Intel Lewisburg device IDs

2016-01-05T17:35:58+00:00

commit cdc5a3110e7c3ae793f367285789a6bc39c962dc upstream.

Adding Intel codename Lewisburg platform device IDs for SMBus.

Signed-off-by: Alexandra Yates 
Reviewed-by: Jean Delvare 
Signed-off-by: Wolfram Sang 
Cc: Oliver Neukum 
Signed-off-by: Jiri Slaby

ima: extend "mask" policy matching support

2015-08-19T06:36:50+00:00

commit 4351c294b8c1028077280f761e158d167b592974 upstream.

The current "mask" policy option matches files opened as MAY_READ,
MAY_WRITE, MAY_APPEND or MAY_EXEC.  This patch extends the "mask"
option to match files opened containing one of these modes.  For
example, "mask=^MAY_READ" would match files opened read-write.

Signed-off-by: Mimi Zohar 
Signed-off-by: Dr. Greg Wettstein 
Signed-off-by: Jiri Slaby

ima: add support for new "euid" policy condition

2015-08-19T06:36:50+00:00

commit 139069eff7388407f19794384c42a534d618ccd7 upstream.

The new "euid" policy condition measures files with the specified
effective uid (euid).  In addition, for CAP_SETUID files it measures
files with the specified uid or suid.

Changelog:
- fixed checkpatch.pl warnings
- fixed avc denied {setuid} messages - based on Roberto's feedback

Signed-off-by: Mimi Zohar 
Signed-off-by: Dr. Greg Wettstein 
Signed-off-by: Jiri Slaby

i2c: i801: Add DeviceIDs for SunrisePoint LP

2015-08-04T14:51:58+00:00

commit 3eee1799aed90e990e02a73a89bfcff1982c74dd upstream.

Signed-off-by: Devin Ryles 
Reviewed-by: Jean Delvare 
Signed-off-by: Wolfram Sang 
Signed-off-by: Jiri Slaby

i2c: i801: Add Device IDs for Intel Sunrise Point PCH

2015-08-04T14:51:58+00:00

commit 3e27a8445c21f8056517f188303827450590d868 upstream.

This patch adds the I2C/SMBus Device IDs for the Intel Sunrise Point PCH.

Signed-off-by: James Ralston 
Signed-off-by: Wolfram Sang 
Signed-off-by: Jiri Slaby

i2c: i801: Add device ID for Intel Wildcat Point PCH

2015-08-04T14:51:57+00:00

commit b299de839157852c563b9f133c8b7e630545a9c3 upstream.

Signed-off-by: Jean Delvare 
Signed-off-by: Wolfram Sang 
Signed-off-by: Jiri Slaby