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authorGustavo A. R. Silva <gustavoars@kernel.org>2023-11-25 15:33:58 -0600
committerPaolo Abeni <pabeni@redhat.com>2023-11-28 12:18:29 +0100
commit45b3fae4675dc1d4ee2d7aefa19d85ee4f891377 (patch)
tree55dc147a15f128b4e9c229e08c427044856e543a
parentfd7f98b2e12a3d96a92bde6640657ec7116f4372 (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.h2
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 {