Linux kernel source tree
Go to file
Paul Kocialkowski 8e770d996e i2c: bcm2835: Clear current buffer pointers and counts after a transfer
[ Upstream commit f275a46594 ]

The driver's interrupt handler checks whether a message is currently
being handled with the curr_msg pointer. When it is NULL, the interrupt
is considered to be unexpected. Similarly, the i2c_start_transfer
routine checks for the remaining number of messages to handle in
num_msgs.

However, these values are never cleared and always keep the message and
number relevant to the latest transfer (which might be done already and
the underlying message memory might have been freed).

When an unexpected interrupt hits with the DONE bit set, the isr will
then try to access the flags field of the curr_msg structure, leading
to a fatal page fault.

The msg_buf and msg_buf_remaining fields are also never cleared at the
end of the transfer, which can lead to similar pitfalls.

Fix these issues by introducing a cleanup function and always calling
it after a transfer is finished.

Fixes: e247454103 ("i2c: bcm2835: Fix hang for writing messages larger than 16 bytes")
Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-03-23 20:09:47 +01:00
arch x86/CPU: Add Icelake model number 2019-03-23 20:09:46 +01:00
block blk-mq: insert rq with DONTPREP to hctx dispatch list when requeue 2019-03-23 20:09:45 +01:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto crypto: ahash - fix another early termination in hash walk 2019-03-23 20:09:40 +01:00
Documentation dt-bindings: eeprom: at24: add "atmel,24c2048" compatible string 2019-02-20 10:25:35 +01:00
drivers i2c: bcm2835: Clear current buffer pointers and counts after a transfer 2019-03-23 20:09:47 +01:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs NFS: Don't use page_file_mapping after removing the page 2019-03-23 20:09:45 +01:00
include KVM: arm/arm64: vgic: Make vgic_dist->lpi_list_lock a raw_spinlock 2019-03-23 20:09:42 +01:00
init Revert "mm: use early_pfn_to_nid in page_ext_init" 2019-03-23 20:09:46 +01:00
ipc ipc/shm.c: use ERR_CAST() for shm_lock() error return 2018-10-05 16:32:04 -07:00
kernel bpf: Fix syscall's stackmap lookup potential deadlock 2019-03-13 14:02:36 -07:00
lib lib/test_kmod.c: potential double free in error handling 2019-03-13 14:02:32 -07:00
LICENSES LICENSES: Remove CC-BY-SA-4.0 license text 2018-10-18 11:28:50 +02:00
mm mm: page_alloc: fix ref bias in page_frag_alloc() for 1-byte allocs 2019-03-23 20:09:46 +01:00
net xprtrdma: Make sure Send CQ is allocated on an existing compvec 2019-03-23 20:09:45 +01:00
samples samples: mei: use /dev/mei0 instead of /dev/mei 2019-02-15 08:10:11 +01:00
scripts scripts/gdb: fix lx-version string output 2019-02-12 19:47:20 +01:00
security missing barriers in some of unix_sock ->addr and ->path accesses 2019-03-19 13:12:41 +01:00
sound ASoC: samsung: Prevent clk_get_rate() calls in atomic context 2019-03-23 20:09:44 +01:00
tools perf trace: Support multiple "vfs_getname" probes 2019-03-13 14:02:37 -07:00
usr initramfs: move gen_initramfs_list.sh from scripts/ to usr/ 2018-08-22 23:21:44 +09:00
virt KVM: arm/arm64: vgic: Always initialize the group of private IRQs 2019-03-23 20:09:43 +01:00
.clang-format clang-format: Set IndentWrappedFunctionNames false 2018-08-01 18:38:51 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap libnvdimm-for-4.19_misc 2018-08-25 18:13:10 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS 9p: remove Ron Minnich from MAINTAINERS 2018-08-17 16:20:26 -07:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS MAINTAINERS: Add Sasha as a stable branch maintainer 2018-12-01 09:37:25 +01:00
Makefile Linux 4.19.30 2019-03-19 13:12:42 +01:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.