YOSHIFUJI Hideaki / 吉藤英明 ecd9883724 ipv6: fix race condition regarding dst->expires and dst->from. ... Eric Dumazet wrote: | Some strange crashes happen in rt6_check_expired(), with access | to random addresses. | | At first glance, it looks like the RTF_EXPIRES and | stuff added in commit 1716a96101 | (ipv6: fix problem with expired dst cache) | are racy : same dst could be manipulated at the same time | on different cpus. | | At some point, our stack believes rt->dst.from contains a dst pointer, | while its really a jiffie value (as rt->dst.expires shares the same area | of memory) | | rt6_update_expires() should be fixed, or am I missing something ? | | CC Neil because of https://bugzilla.redhat.com/show_bug.cgi?id=892060 Because we do not have any locks for dst_entry, we cannot change essential structure in the entry; e.g., we cannot change reference to other entity. To fix this issue, split 'from' and 'expires' field in dst_entry out of union. Once it is 'from' is assigned in the constructor, keep the reference until the very last stage of the life time of the object. Of course, it is unsafe to change 'from', so make rt6_set_from simple just for fresh entries. Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Reported-by: Neil Horman <nhorman@tuxdriver.com> CC: Gao Feng <gaofeng@cn.fujitsu.com> Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Reported-by: Steinar H. Gunderson <sesse@google.com> Reviewed-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2013-02-20 15:11:45 -05:00
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acpi	PCI changes for the v3.8 merge window:	2012-12-13 12:14:47 -08:00
asm-generic	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k	2013-01-23 13:31:15 -08:00
clocksource
crypto
drm	Merge branch 'drm-intel-fixes' of git://people.freedesktop.org/~danvet/drm-intel	2013-01-11 07:52:48 +10:00
keys
linux	net: fix a build failure when !CONFIG_PROC_FS	2013-02-19 13:18:13 -05:00
math-emu
media
memory
misc
net	ipv6: fix race condition regarding dst->expires and dst->from.	2013-02-20 15:11:45 -05:00
pcmcia
ras
rdma	UAPI: Remove empty Kbuild files	2013-01-02 17:36:10 -08:00
rxrpc
scsi	SCSI misc on 20121212	2012-12-13 19:20:31 -08:00
sound	Merge remote-tracking branch 'asoc/fix/cs4271' into tmp	2013-01-10 12:22:11 +00:00
target	target: Introduce TCM_NO_SENSE	2013-01-10 20:06:08 -08:00
trace	Various bug fixes for ext4. Perhaps the most serious bug fixed is one	2013-01-02 09:57:34 -08:00
uapi	Merge branch 'master' of git://1984.lsi.us.es/nf-next	2013-02-18 23:42:09 -05:00
video	Merge branch 'omap-for-v3.8/fixes-for-merge-window' into omap-for-v3.8/fixes-for-merge-window-v2	2012-12-16 11:28:10 -08:00
xen	Bugfixes:	2012-12-18 12:26:54 -08:00
Kbuild	UAPI: Remove empty Kbuild files	2013-01-02 17:36:10 -08:00