On Mon, Oct 27, 2025 at 11:08:38PM +0800, Miaoqian Lin wrote:
The function has a memory leak when kvrealloc() fails. The function directly assigns NULL to the markers pointer, losing the reference to the previously allocated memory. This causes kvfree() in pt_dump_init() to free NULL instead of the leaked memory.
Fix by:
- Using kvrealloc() uniformly for all allocations
- Using a temporary variable to preserve the original pointer until allocation succeeds
- Removing the error path that sets markers_cnt=0 to keep consistency between markers and markers_cnt
Found via static analysis and this is similar to commit 42378a9ca553 ("bpf, verifier: Fix memory leak in array reallocation for stack state")
Fixes: d0e7915d2ad3 ("s390/mm/ptdump: Generate address marker array dynamically") Cc: stable@vger.kernel.org Signed-off-by: Miaoqian Lin linmq006@gmail.com
changes in v2:
- update the fixing logic to prevent memory leak in v1
v1 link: https://lore.kernel.org/all/20251026091351.36275-1-linmq006@gmail.com/
arch/s390/mm/dump_pagetables.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-)
Applied, thanks!