ext4: use memtostr_pad() for s_volume_name

As with the other strings in struct ext4_super_block, s_volume_name is not NUL terminated. The other strings were marked in commit 072ebb3 ("ext4: add nonstring annotations to ext4.h"). Using strscpy() isn't the right replacement for strncpy(); it should use memtostr_pad() instead. Reported-by: [email protected] Closes: https://lore.kernel.org/all/[email protected]/ Fixes: 744a563 ("ext4: replace deprecated strncpy with alternatives") Signed-off-by: Kees Cook <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
torvalds · Jul 5, 2024 · be27cd6 · be27cd6
1 parent 7c73ddb
commit be27cd6
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Showing 2 changed files with 2 additions and 2 deletions.
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
@@ -1347,7 +1347,7 @@ struct ext4_super_block {
 /*60*/ __le32 s_feature_incompat; /* incompatible feature set */
  __le32 s_feature_ro_compat; /* readonly-compatible feature set */
 /*68*/ __u8 s_uuid[16]; /* 128-bit uuid for volume */
-/*78*/ char s_volume_name[EXT4_LABEL_MAX]; /* volume name */
+/*78*/ char s_volume_name[EXT4_LABEL_MAX] __nonstring; /* volume name */
 /*88*/ char s_last_mounted[64] __nonstring; /* directory where last mounted */
 /*C8*/ __le32 s_algorithm_usage_bitmap; /* For compression */
  /*

diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
@@ -1151,7 +1151,7 @@ static int ext4_ioctl_getlabel(struct ext4_sb_info *sbi, char __user *user_label
  BUILD_BUG_ON(EXT4_LABEL_MAX >= FSLABEL_MAX);
 
  lock_buffer(sbi->s_sbh);
- strscpy_pad(label, sbi->s_es->s_volume_name);
+ memtostr_pad(label, sbi->s_es->s_volume_name);
  unlock_buffer(sbi->s_sbh);
 
  if (copy_to_user(user_label, label, sizeof(label)))