On 10/14/24 15:50, Breno Leitao wrote:
Introduce a fault injection mechanism to force skb reallocation. The primary goal is to catch bugs related to pointer invalidation after potential skb reallocation. The fault injection mechanism aims to identify scenarios where callers retain pointers to various headers in the skb but fail to reload these pointers after calling a function that may reallocate the data. This type of bug can lead to memory corruption or crashes if the old, now-invalid pointers are used. By forcing reallocation through fault injection, we can stress-test code paths and ensure proper pointer management after potential skb reallocations. Add a hook for fault injection in the following functions: * pskb_trim_rcsum() * pskb_may_pull_reason() * pskb_trim() As the other fault injection mechanism, protect it under a debug Kconfig called CONFIG_FAIL_SKB_FORCE_REALLOC. This patch was *heavily* inspired by Jakub's proposal from: https://lore.kernel.org/all/20240719174140.47a868e6@xxxxxxxxxx/ CC: Akinobu Mita <akinobu.mita@xxxxxxxxx> Suggested-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
I'm sorry to nit-pick, but checkpatch laments that the new command line argument lacks documentation in Documentation/admin-guide/kernel-parameters.txt, and I feel that could be actually useful.
With that, feel free to include my ack in the next revision, Thanks! Paolo
