tree 12b5614f7b8b496cd814fcc48a590f0702d05cbb
parent aa5d35e350f6587a17e7b17cc26eb0bfd7dda04c
author Lasse Collin <lasse.collin@tukaani.org> 1633901500 +0800
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1637240638 +0100

lib/xz: Validate the value before assigning it to an enum variable

[ Upstream commit 4f8d7abaa413c34da9d751289849dbfb7c977d05 ]

This might matter, for example, if the underlying type of enum xz_check
was a signed char. In such a case the validation wouldn't have caught an
unsupported header. I don't know if this problem can occur in the kernel
on any arch but it's still good to fix it because some people might copy
the XZ code to their own projects from Linux instead of the upstream
XZ Embedded repository.

This change may increase the code size by a few bytes. An alternative
would have been to use an unsigned int instead of enum xz_check but
using an enumeration looks cleaner.

Link: https://lore.kernel.org/r/20211010213145.17462-3-xiang@kernel.org
Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>