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Marc Kleine-Budde c812948744 can: skb: alloc_can{,fd}_skb(): set "cf" to NULL if skb allocation fails
The handling of CAN bus errors typically consist of allocating a CAN
error SKB using alloc_can_err_skb() followed by stats handling and
filling the error details in the newly allocated CAN error SKB. Even
if the allocation of the SKB fails the stats handling should not be
skipped.

The common pattern in CAN drivers is to allocate the skb and work on
the struct can_frame pointer "cf", if it has been assigned by
alloc_can_err_skb().

|	skb = alloc_can_err_skb(priv->ndev, &cf);
|
| 	/* RX errors */
| 	if (bdiag1 & (MCP251XFD_REG_BDIAG1_DCRCERR |
| 		      MCP251XFD_REG_BDIAG1_NCRCERR)) {
| 		netdev_dbg(priv->ndev, "CRC error\n");
|
| 		stats->rx_errors++;
| 		if (cf)
| 			cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
| 	}

In case of an OOM alloc_can_err_skb() returns NULL, but doesn't set
"cf" to NULL as well. For the above pattern to work the "cf" has to be
initialized to NULL, which is easily forgotten.

To solve this kind of problems, set "cf" to NULL if
alloc_can_err_skb() returns NULL.

Link: https://lore.kernel.org/r/20210402102245.1512583-1-mkl@pengutronix.de
Suggested-by: Vincent MAILHOL <mailhol.vincent@wanadoo.fr>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-04-07 09:31:19 +02:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-04-02 11:03:07 -07:00
block block: Discard page cache of zone reset target range 2021-03-11 11:49:25 -07:00
certs certs: Replace K{U,G}IDT_INIT() with GLOBAL_ROOT_{U,G}ID 2021-01-21 16:16:10 +00:00
crypto crypto: mips/poly1305 - enable for all MIPS processors 2021-03-08 11:52:17 +01:00
Documentation docs: ethtool: correct quotes 2021-04-06 16:56:58 -07:00
drivers can: skb: alloc_can{,fd}_skb(): set "cf" to NULL if skb allocation fails 2021-04-07 09:31:19 +02:00
fs fs/jffs2: Delete obsolete TODO file 2021-03-30 16:54:49 -07:00
include Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2021-04-06 16:36:41 -07:00
init Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-03-25 15:31:22 -07:00
ipc fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-04-02 11:03:07 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-03-25 15:31:22 -07:00
LICENSES LICENSES: Add the CC-BY-4.0 license 2020-12-08 10:33:27 -07:00
mm Merge branch 'akpm' (patches from Andrew) 2021-03-25 11:43:43 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2021-04-06 16:36:41 -07:00
samples samples: bpf: Do not unload prog within xdpsock 2021-03-30 09:24:39 -07:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-03-25 15:31:22 -07:00
security Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-03-25 15:31:22 -07:00
sound sound fixes for 5.12-rc4 2021-03-19 09:53:32 -07:00
tools selftests: mptcp: dump more info on mpjoin errors 2021-04-02 14:21:51 -07:00
usr Kbuild updates for v5.12 2021-02-25 10:17:31 -08:00
virt KVM: x86/mmu: Consider the hva in mmu_notifier retry 2021-02-22 13:16:53 -05:00
.clang-format cxl for 5.12 2021-02-24 09:38:36 -08:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore clang-lto series for v5.12-rc1 2021-02-23 09:28:51 -08:00
.mailmap Merge branch 'akpm' (patches from Andrew) 2021-03-25 11:43:43 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS treewide: Miguel has moved 2021-02-26 09:41:03 -08:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: Update MCAN MMIO device driver maintainer 2021-03-30 09:31:54 +02:00
Makefile Linux 5.12-rc4 2021-03-21 14:56:43 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -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.

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.