efivarfs: Fix memory leak of efivarfs_fs_info in fs_context error paths

When processing mount options, efivarfs allocates efivarfs_fs_info (sfi)
early in fs_context initialization. However, sfi is associated with the
superblock and typically freed when the superblock is destroyed. If the
fs_context is released (final put) before fill_super is called—such as
on error paths or during reconfiguration—the sfi structure would leak,
as ownership never transfers to the superblock.

Implement the .free callback in efivarfs_context_ops to ensure any
allocated sfi is properly freed if the fs_context is torn down before
fill_super, preventing this memory leak.

Suggested-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Fixes: 5329aa5101 ("efivarfs: Add uid/gid mount options")
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
This commit is contained in:
Breno Leitao 2025-07-16 08:23:12 -07:00 committed by Ard Biesheuvel
parent f8b53cc917
commit 64e135f1ea

View File

@ -390,10 +390,16 @@ static int efivarfs_reconfigure(struct fs_context *fc)
return 0;
}
static void efivarfs_free(struct fs_context *fc)
{
kfree(fc->s_fs_info);
}
static const struct fs_context_operations efivarfs_context_ops = {
.get_tree = efivarfs_get_tree,
.parse_param = efivarfs_parse_param,
.reconfigure = efivarfs_reconfigure,
.free = efivarfs_free,
};
static int efivarfs_check_missing(efi_char16_t *name16, efi_guid_t vendor,