On Wed, 24 Apr 2024 13:44:31 PDT (-0700), alex@xxxxxxxx wrote:
Hi Stefan, On 26/03/2024 04:20, Stefan O'Rear wrote:Commit 04d82a6d0881 ("binfmt_flat: allow not offsetting data start") introduced a RISC-V specific variant of the FLAT format which does not allocate any space for the (obsolescent) array of shared library pointers. However, it did not disable the code which initializes the array, resulting in the corruption of sizeof(long) bytes before the DATA segment, generally the end of the TEXT segment. Use CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET to guard initialization the shared library pointer region so that it will only be initialized if space is reserved for it. Fixes: 04d82a6d0881 ("binfmt_flat: allow not offsetting data start") Signed-off-by: Stefan O'Rear <sorear@xxxxxxxxxxxx> Tested-by: Waldemar Brodkorb <wbx@xxxxxxxxxxx> --- fs/binfmt_flat.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c index c26545d71d39..70c2b68988f4 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -879,6 +879,7 @@ static int load_flat_binary(struct linux_binprm *bprm) if (res < 0) return res; +#ifndef CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET /* Update data segment pointers for all libraries */ for (i = 0; i < MAX_SHARED_LIBS; i++) { if (!libinfo.lib_list[i].loaded) @@ -893,6 +894,7 @@ static int load_flat_binary(struct linux_binprm *bprm) return -EFAULT; } } +#endif set_binfmt(&flat_format);I have this fix on my list for quite some time, will you respin a new version for 6.9?
IIRC we asked on IRC and Sorear wasn't going to respin the patch, so unless someone else wants to pick it up I think it's just going to get lost.
Thanks, Alex
