From: Zhen Ni Date: Mon, 13 Oct 2025 11:41:51 +0000 (+0800) Subject: fs: Fix uninitialized 'offp' in statmount_string() X-Git-Tag: v6.18-rc7~32^2~11 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=0778ac7df5137d5041783fadfc201f8fd55a1d9b;p=thirdparty%2Flinux.git fs: Fix uninitialized 'offp' in statmount_string() In statmount_string(), most flags assign an output offset pointer (offp) which is later updated with the string offset. However, the STATMOUNT_MNT_UIDMAP and STATMOUNT_MNT_GIDMAP cases directly set the struct fields instead of using offp. This leaves offp uninitialized, leading to a possible uninitialized dereference when *offp is updated. Fix it by assigning offp for UIDMAP and GIDMAP as well, keeping the code path consistent. Fixes: 37c4a9590e1e ("statmount: allow to retrieve idmappings") Fixes: e52e97f09fb6 ("statmount: let unset strings be empty") Cc: stable@vger.kernel.org Signed-off-by: Zhen Ni Link: https://patch.msgid.link/20251013114151.664341-1-zhen.ni@easystack.cn Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- diff --git a/fs/namespace.c b/fs/namespace.c index d82910f33dc4..5b5ab2ae238b 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -5454,11 +5454,11 @@ static int statmount_string(struct kstatmount *s, u64 flag) ret = statmount_sb_source(s, seq); break; case STATMOUNT_MNT_UIDMAP: - sm->mnt_uidmap = start; + offp = &sm->mnt_uidmap; ret = statmount_mnt_uidmap(s, seq); break; case STATMOUNT_MNT_GIDMAP: - sm->mnt_gidmap = start; + offp = &sm->mnt_gidmap; ret = statmount_mnt_gidmap(s, seq); break; default: