kernel/linux.git/lib, branch v4.14.156

idr: Fix idr_get_next race with idr_remove

2019-11-24T07:22:46+00:00

commit 5c089fd0c73411f2170ab795c9ffc16718c7d007 upstream. If the entry is deleted from the IDR between the call to radix_tree_iter_find() and rcu_dereference_raw(), idr_get_next() will return NULL, which will end the iteration prematurely. We should instead continue to the next entry in the IDR. This only happens if the iteration is protected by the RCU lock. Most IDR users use a spinlock or semaphore to exclude simultaneous modifications. It was noticed once the PID allocator was converted to use the IDR, as it uses the RCU lock, but there may be other users elsewhere in the kernel. We can't use the normal pattern of calling radix_tree_deref_retry() (which catches both a retry entry in a leaf node and a node entry in the root) as the IDR supports storing entries which are unaligned, which will trigger an infinite loop if they are encountered. Instead, we have to explicitly check whether the entry is a retry entry. Fixes: 0a835c4f090a ("Reimplement IDR and IDA using the radix tree") Reported-by: Brendan Gregg Tested-by: Brendan Gregg Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Greg Kroah-Hartman

lib/scatterlist: Introduce sgl_alloc() and sgl_free()

2019-11-12T18:18:30+00:00

commit e80a0af4759a164214f02da157a3800753ce135f upstream. Many kernel drivers contain code that allocates and frees both a scatterlist and the pages that populate that scatterlist. Introduce functions in lib/scatterlist.c that perform these tasks instead of duplicating this functionality in multiple drivers. Only include these functions in the build if CONFIG_SGL_ALLOC=y to avoid that the kernel size increases if this functionality is not used. Signed-off-by: Bart Van Assche Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

dump_stack: avoid the livelock of the dump_lock

2019-11-12T18:18:01+00:00

commit 5cbf2fff3bba8d3c6a4d47c1754de1cf57e2b01f upstream. In the current code, we use the atomic_cmpxchg() to serialize the output of the dump_stack(), but this implementation suffers the thundering herd problem. We have observed such kind of livelock on a Marvell cn96xx board(24 cpus) when heavily using the dump_stack() in a kprobe handler. Actually we can let the competitors to wait for the releasing of the lock before jumping to atomic_cmpxchg(). This will definitely mitigate the thundering herd problem. Thanks Linus for the suggestion. [akpm@linux-foundation.org: fix comment] Link: http://lkml.kernel.org/r/20191030031637.6025-1-haokexin@gmail.com Fixes: b58d977432c8 ("dump_stack: serialize the output from dump_stack()") Signed-off-by: Kevin Hao Suggested-by: Linus Torvalds Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

kmemleak: increase DEBUG_KMEMLEAK_EARLY_LOG_SIZE default to 16K

2019-10-07T16:55:15+00:00

[ Upstream commit b751c52bb587ae66f773b15204ef7a147467f4c7 ] The current default value (400) is too low on many systems (e.g. some ARM64 platform takes up 1000+ entries). syzbot uses 16000 as default value, and has proved to be enough on beefy configurations, so let's pick that value. This consumes more RAM on boot (each entry is 160 bytes, so in total ~2.5MB of RAM), but the memory would later be freed (early_log is __initdata). Link: http://lkml.kernel.org/r/20190730154027.101525-1-drinkcat@chromium.org Signed-off-by: Nicolas Boichat Suggested-by: Dmitry Vyukov Acked-by: Catalin Marinas Acked-by: Dmitry Vyukov Cc: Masahiro Yamada Cc: Kees Cook Cc: Petr Mladek Cc: Thomas Gleixner Cc: Tetsuo Handa Cc: Joe Lawrence Cc: Uladzislau Rezki Cc: Andy Shevchenko Cc: Stephen Rothwell Cc: Andrey Ryabinin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

test_firmware: fix a memory leak bug

2019-08-16T08:13:55+00:00

[ Upstream commit d4fddac5a51c378c5d3e68658816c37132611e1f ] In test_firmware_init(), the buffer pointed to by the global pointer 'test_fw_config' is allocated through kzalloc(). Then, the buffer is initialized in __test_firmware_config_init(). In the case that the initialization fails, the following execution in test_firmware_init() needs to be terminated with an error code returned to indicate this failure. However, the allocated buffer is not freed on this execution path, leading to a memory leak bug. To fix the above issue, free the allocated buffer before returning from test_firmware_init(). Signed-off-by: Wenwen Wang Link: https://lore.kernel.org/r/1563084696-6865-1-git-send-email-wang6495@umn.edu Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

lib/strscpy: Shut up KASAN false-positives in strscpy()

2019-07-31T05:28:44+00:00

[ Upstream commit 1a3241ff10d038ecd096d03380327f2a0b5840a6 ] strscpy() performs the word-at-a-time optimistic reads. So it may may access the memory past the end of the object, which is perfectly fine since strscpy() doesn't use that (past-the-end) data and makes sure the optimistic read won't cross a page boundary. Use new read_word_at_a_time() to shut up the KASAN. Note that this potentially could hide some bugs. In example bellow, stscpy() will copy more than we should (1-3 extra uninitialized bytes): char dst[8]; char *src; src = kmalloc(5, GFP_KERNEL); memset(src, 0xff, 5); strscpy(dst, src, 8); Signed-off-by: Andrey Ryabinin Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

lib/scatterlist: Fix mapping iterator when sg->offset is greater than PAGE_SIZE

2019-07-31T05:28:37+00:00

commit aeb87246537a83c2aff482f3f34a2e0991e02cbc upstream. All mapping iterator logic is based on the assumption that sg->offset is always lower than PAGE_SIZE. But there are situations where sg->offset is such that the SG item is on the second page. In that case sg_copy_to_buffer() fails properly copying the data into the buffer. One of the reason is that the data will be outside the kmapped area used to access that data. This patch fixes the issue by adjusting the mapping iterator offset and pgoffset fields such that offset is always lower than PAGE_SIZE. Signed-off-by: Christophe Leroy Fixes: 4225fc8555a9 ("lib/scatterlist: use page iterator in the mapping iterator") Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

rslib: Fix handling of of caller provided syndrome

2019-07-31T05:28:30+00:00

[ Upstream commit ef4d6a8556b637ad27c8c2a2cff1dda3da38e9a9 ] Check if the syndrome provided by the caller is zero, and act accordingly. Signed-off-by: Ferdinand Blomqvist Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20190620141039.9874-6-ferdinand.blomqvist@gmail.com Signed-off-by: Sasha Levin

rslib: Fix decoding of shortened codes

2019-07-31T05:28:30+00:00

[ Upstream commit 2034a42d1747fc1e1eeef2c6f1789c4d0762cb9c ] The decoding of shortenend codes is broken. It only works as expected if there are no erasures. When decoding with erasures, Lambda (the error and erasure locator polynomial) is initialized from the given erasure positions. The pad parameter is not accounted for by the initialisation code, and hence Lambda is initialized from incorrect erasure positions. The fix is to adjust the erasure positions by the supplied pad. Signed-off-by: Ferdinand Blomqvist Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20190620141039.9874-3-ferdinand.blomqvist@gmail.com Signed-off-by: Sasha Levin

lib/mpi: Fix karactx leak in mpi_powm

2019-07-10T07:54:40+00:00

commit c8ea9fce2baf7b643384f36f29e4194fa40d33a6 upstream. Sometimes mpi_powm will leak karactx because a memory allocation failure causes a bail-out that skips the freeing of karactx. This patch moves the freeing of karactx to the end of the function like everything else so that it can't be skipped. Reported-by: syzbot+f7baccc38dcc1e094e77@syzkaller.appspotmail.com Fixes: cdec9cb5167a ("crypto: GnuPG based MPI lib - source files...") Cc: Signed-off-by: Herbert Xu Reviewed-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman