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authorVladimir Oltean <vladimir.oltean@nxp.com>2024-10-02 14:51:50 -0700
committerJakub Kicinski <kuba@kernel.org>2024-10-03 15:32:03 -0700
commit8b3e26677bc64d42d2f38d9abc8dccc09d8a4259 (patch)
tree45fdf74fbb91eaefa3614816c319c50031a3eb75 /lib/packing.c
parentf66ebf37d69cc700ca884c6a18c2258caf8b151b (diff)
lib: packing: refuse operating on bit indices which exceed size of buffer
While reworking the implementation, it became apparent that this check does not exist. There is no functional issue yet, because at call sites, "startbit" and "endbit" are always hardcoded to correct values, and never come from the user. Even with the upcoming support of arbitrary buffer lengths, the "startbit >= 8 * pbuflen" check will remain correct. This is because we intend to always interpret the packed buffer in a way that avoids discontinuities in the available bit indices. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com> Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://patch.msgid.link/20241002-packing-kunit-tests-and-split-pack-unpack-v2-1-8373e551eae3@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'lib/packing.c')
-rw-r--r--lib/packing.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/lib/packing.c b/lib/packing.c
index 3f656167c17e..439125286d2b 100644
--- a/lib/packing.c
+++ b/lib/packing.c
@@ -86,8 +86,10 @@ int packing(void *pbuf, u64 *uval, int startbit, int endbit, size_t pbuflen,
*/
int plogical_first_u8, plogical_last_u8, box;
- /* startbit is expected to be larger than endbit */
- if (startbit < endbit)
+ /* startbit is expected to be larger than endbit, and both are
+ * expected to be within the logically addressable range of the buffer.
+ */
+ if (unlikely(startbit < endbit || startbit >= 8 * pbuflen || endbit < 0))
/* Invalid function call */
return -EINVAL;