diff options
author | Gustavo A. R. Silva <gustavoars@kernel.org> | 2023-11-25 15:33:58 -0600 |
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committer | Paolo Abeni <pabeni@redhat.com> | 2023-11-28 12:18:29 +0100 |
commit | 45b3fae4675dc1d4ee2d7aefa19d85ee4f891377 (patch) | |
tree | 55dc147a15f128b4e9c229e08c427044856e543a | |
parent | fd7f98b2e12a3d96a92bde6640657ec7116f4372 (diff) |
neighbour: Fix __randomize_layout crash in struct neighbour
Previously, one-element and zero-length arrays were treated as true
flexible arrays, even though they are actually "fake" flex arrays.
The __randomize_layout would leave them untouched at the end of the
struct, similarly to proper C99 flex-array members.
However, this approach changed with commit 1ee60356c2dc ("gcc-plugins:
randstruct: Only warn about true flexible arrays"). Now, only C99
flexible-array members will remain untouched at the end of the struct,
while one-element and zero-length arrays will be subject to randomization.
Fix a `__randomize_layout` crash in `struct neighbour` by transforming
zero-length array `primary_key` into a proper C99 flexible-array member.
Fixes: 1ee60356c2dc ("gcc-plugins: randstruct: Only warn about true flexible arrays")
Closes: https://lore.kernel.org/linux-hardening/20231124102458.GB1503258@e124191.cambridge.arm.com/
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/ZWJoRsJGnCPdJ3+2@work
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
-rw-r--r-- | include/net/neighbour.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/net/neighbour.h b/include/net/neighbour.h index 07022bb0d44d..0d28172193fa 100644 --- a/include/net/neighbour.h +++ b/include/net/neighbour.h @@ -162,7 +162,7 @@ struct neighbour { struct rcu_head rcu; struct net_device *dev; netdevice_tracker dev_tracker; - u8 primary_key[0]; + u8 primary_key[]; } __randomize_layout; struct neigh_ops { |