From: Ruipeng Qi <ruipengqi3@gmail.com> stable inclusion from stable-v5.10.252 commit d47234840aeb4182ed3ee795c578b1dfa9cbd25b category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/14671 CVE: CVE-2026-43124 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... ---------------------------------------------------------------------- [ Upstream commit 05363abc7625cf18c96e67f50673cd07f11da5e9 ] In persistent_ram_vmap(), vmap() may return NULL on failure. If offset is non-zero, adding offset_in_page(start) causes the function to return a non-NULL pointer even though the mapping failed. persistent_ram_buffer_map() therefore incorrectly returns success. Subsequent access to prz->buffer may dereference an invalid address and cause crashes. Add proper NULL checking for vmap() failures. Signed-off-by: Ruipeng Qi <ruipengqi3@gmail.com> Link: https://patch.msgid.link/20260203020358.3315299-1-ruipengqi3@gmail.com Signed-off-by: Kees Cook <kees@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Luo Gengkun <luogengkun2@huawei.com> --- fs/pstore/ram_core.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c index 588392e6f531..749a9fa36b62 100644 --- a/fs/pstore/ram_core.c +++ b/fs/pstore/ram_core.c @@ -433,6 +433,13 @@ static void *persistent_ram_vmap(phys_addr_t start, size_t size, vaddr = vmap(pages, page_count, VM_MAP | VM_IOREMAP, prot); kfree(pages); + /* + * vmap() may fail and return NULL. Do not add the offset in this + * case, otherwise a NULL mapping would appear successful. + */ + if (!vaddr) + return NULL; + /* * Since vmap() uses page granularity, we must add the offset * into the page here, to get the byte granularity address -- 2.34.1