The range passed to user_access_begin() by strncpy_from_user() and
strnlen_user() starts at 'src' and goes up to the limit of userspace
although reads will be limited by the 'count' param.
On 32 bits powerpc (book3s/32) access has to be granted for each
256Mbytes segment and the cost increases with the number of segments to
unlock.
Limit the range with 'count' param.
Fixes: 594cc251fd ("make 'user_access_begin()' do 'access_ok()'")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull XArray fixes from Matthew Wilcox:
"Primarily bugfixes, mostly around handling index wrap-around
correctly.
A couple of doc fixes and adding missing APIs.
I had an oops live on stage at linux.conf.au this year, and it turned
out to be a bug in xas_find() which I can't prove isn't triggerable in
the current codebase. Then in looking for the bug, I spotted two more
bugs.
The bots have had a few days to chew on this with no problems
reported, and it passes the test-suite (which now has more tests to
make sure these problems don't come back)"
* tag 'xarray-5.5' of git://git.infradead.org/users/willy/linux-dax:
XArray: Add xa_for_each_range
XArray: Fix xas_find returning too many entries
XArray: Fix xa_find_after with multi-index entries
XArray: Fix infinite loop with entry at ULONG_MAX
XArray: Add wrappers for nested spinlocks
XArray: Improve documentation of search marks
XArray: Fix xas_pause at ULONG_MAX
If you call xas_find() with the initial index > max, it should have
returned NULL but was returning the entry at index.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: stable@vger.kernel.org
If the entry is of an order which is a multiple of XA_CHUNK_SIZE,
the current detection of sibling entries does not work. Factor out
an xas_sibling() function to make xa_find_after() a little more
understandable, and write a new implementation that doesn't suffer from
the same bug.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: stable@vger.kernel.org
If there is an entry at ULONG_MAX, xa_for_each() will overflow the
'index + 1' in xa_find_after() and wrap around to 0. Catch this case
and terminate the loop by returning NULL.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: stable@vger.kernel.org
Pull vfs fixes from Al Viro:
"Eric's s_inodes softlockup fixes + Jan's fix for recent regression
from pipe rework"
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: call fsnotify_sb_delete after evict_inodes
fs: avoid softlockups in s_inodes iterators
pipe: Fix bogus dereference in iov_iter_alignment()
Pull block fixes from Jens Axboe:
"Let's try this one again, this time without the compat_ioctl changes.
We've got those fixed up, but that can go out next week.
This contains:
- block queue flush lockdep annotation (Bart)
- Type fix for bsg_queue_rq() (Bart)
- Three dasd fixes (Stefan, Jan)
- nbd deadlock fix (Mike)
- Error handling bio user map fix (Yang)
- iocost fix (Tejun)
- sbitmap waitqueue addition fix that affects the kyber IO scheduler
(David)"
* tag 'block-5.5-20191221' of git://git.kernel.dk/linux-block:
sbitmap: only queue kyber's wait callback if not already active
block: fix memleak when __blk_rq_map_user_iov() is failed
s390/dasd: fix typo in copyright statement
s390/dasd: fix memleak in path handling error case
s390/dasd/cio: Interpret ccw_device_get_mdc return value correctly
block: Fix a lockdep complaint triggered by request queue flushing
block: Fix the type of 'sts' in bsg_queue_rq()
block: end bio with BLK_STS_AGAIN in case of non-mq devs and REQ_NOWAIT
nbd: fix shutdown and recv work deadlock v2
iocost: over-budget forced IOs should schedule async delay
Under heavy loads where the kyber I/O scheduler hits the token limits for
its scheduling domains, kyber can become stuck. When active requests
complete, kyber may not be woken up leaving the I/O requests in kyber
stuck.
This stuck state is due to a race condition with kyber and the sbitmap
functions it uses to run a callback when enough requests have completed.
The running of a sbt_wait callback can race with the attempt to insert the
sbt_wait. Since sbitmap_del_wait_queue removes the sbt_wait from the list
first then sets the sbq field to NULL, kyber can see the item as not on a
list but the call to sbitmap_add_wait_queue will see sbq as non-NULL. This
results in the sbt_wait being inserted onto the wait list but ws_active
doesn't get incremented. So the sbitmap queue does not know there is a
waiter on a wait list.
Since sbitmap doesn't think there is a waiter, kyber may never be
informed that there are domain tokens available and the I/O never advances.
With the sbt_wait on a wait list, kyber believes it has an active waiter
so cannot insert a new waiter when reaching the domain's full state.
This race can be fixed by only adding the sbt_wait to the queue if the
sbq field is NULL. If sbq is not NULL, there is already an action active
which will trigger the re-running of kyber. Let it run and add the
sbt_wait to the wait list if still needing to wait.
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Jeffery <djeffery@redhat.com>
Reported-by: John Pittman <jpittman@redhat.com>
Tested-by: John Pittman <jpittman@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We cannot look at 'i->pipe' unless we know the iter is a pipe. Move the
ring_size load to a branch in iov_iter_alignment() where we've already
checked the iter is a pipe to avoid bogus dereference.
Reported-by: syzbot+bea68382bae9490e7dd6@syzkaller.appspotmail.com
Fixes: 8cefc107ca ("pipe: Use head and tail pointers for the ring, not cursor and length")
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Newer versions of awk spit out these fun warnings:
awk: ../lib/raid6/unroll.awk:16: warning: regexp escape sequence `\#' is not a known regexp operator
As commit 700c1018b8 ("x86/insn: Fix awk regexp warnings") showed, it
turns out that there are a number of awk strings that do not need to be
escaped and newer versions of awk now warn about this.
Fix the string up so that no warning is produced. The exact same kernel
module gets created before and after this patch, showing that it wasn't
needed.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20191206152600.GA75093@kroah.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull ARM SoC driver updates from Olof Johansson:
"Various driver updates for platforms:
- A larger set of work on Tegra 2/3 around memory controller and
regulator features, some fuse cleanups, etc..
- MMP platform drivers, in particular for USB PHY, and other smaller
additions.
- Samsung Exynos 5422 driver for DMC (dynamic memory configuration),
and ASV (adaptive voltage), allowing the platform to run at more
optimal operating points.
- Misc refactorings and support for RZ/G2N and R8A774B1 from Renesas
- Clock/reset control driver for TI/OMAP
- Meson-A1 reset controller support
- Qualcomm sdm845 and sda845 SoC IDs for socinfo"
* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (150 commits)
firmware: arm_scmi: Fix doorbell ring logic for !CONFIG_64BIT
soc: fsl: add RCPM driver
dt-bindings: fsl: rcpm: Add 'little-endian' and update Chassis definition
memory: tegra: Consolidate registers definition into common header
memory: tegra: Ensure timing control debug features are disabled
memory: tegra: Introduce Tegra30 EMC driver
memory: tegra: Do not handle error from wait_for_completion_timeout()
memory: tegra: Increase handshake timeout on Tegra20
memory: tegra: Print a brief info message about EMC timings
memory: tegra: Pre-configure debug register on Tegra20
memory: tegra: Include io.h instead of iopoll.h
memory: tegra: Adapt for Tegra20 clock driver changes
memory: tegra: Don't set EMC rate to maximum on probe for Tegra20
memory: tegra: Add gr2d and gr3d to DRM IOMMU group
memory: tegra: Set DMA mask based on supported address bits
soc: at91: Add Atmel SFR SN (Serial Number) support
memory: atmel-ebi: switch to SPDX license identifiers
memory: atmel-ebi: move NUM_CS definition inside EBI driver
soc: mediatek: Refactor bus protection control
soc: mediatek: Refactor sram control
...
