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When using ip_set with counters and comment, traffic causes the kernel
to panic on 32-bit ARM:
Alignment trap: not handling instruction e1b82f9f at [<bf01b0dc>]
Unhandled fault: alignment exception (0x221) at 0xea08133c
PC is at ip_set_match_extensions+0xe0/0x224 [ip_set]
The problem occurs when we try to update the 64-bit counters - the
faulting address above is not 64-bit aligned. The problem occurs
due to the way elements are allocated, for example:
set->dsize = ip_set_elem_len(set, tb, 0, 0);
map = ip_set_alloc(sizeof(*map) + elements * set->dsize);
If the element has a requirement for a member to be 64-bit aligned,
and set->dsize is not a multiple of 8, but is a multiple of four,
then every odd numbered elements will be misaligned - and hitting
an atomic64_add() on that element will cause the kernel to panic.
ip_set_elem_len() must return a size that is rounded to the maximum
alignment of any extension field stored in the element. This change
ensures that is the case.
Fixes: 95ad1f4a93 ("netfilter: ipset: Fix extension alignment")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Linux kernel
============
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In order to build the documentation, use ``make htmldocs`` or
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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
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the problems which may result by upgrading your kernel.