6.11-stable review patch. If anyone has any objections, please let me know.
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From: Yuezhang Mo Yuezhang.Mo@sony.com
commit 184fa506e392eb78364d9283c961217ff2c0617b upstream.
In the case of the directory size is greater than or equal to the cluster size, if start_clu becomes an EOF cluster(an invalid cluster) due to file system corruption, then the directory entry where ei->hint_femp.eidx hint is outside the directory, resulting in an out-of-bounds access, which may cause further file system corruption.
This commit adds a check for start_clu, if it is an invalid cluster, the file or directory will be treated as empty.
Cc: stable@vger.kernel.org Signed-off-by: Yuezhang Mo Yuezhang.Mo@sony.com Co-developed-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/exfat/namei.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-)
--- a/fs/exfat/namei.c +++ b/fs/exfat/namei.c @@ -637,14 +637,26 @@ static int exfat_find(struct inode *dir, info->size = le64_to_cpu(ep2->dentry.stream.valid_size); info->valid_size = le64_to_cpu(ep2->dentry.stream.valid_size); info->size = le64_to_cpu(ep2->dentry.stream.size); + + info->start_clu = le32_to_cpu(ep2->dentry.stream.start_clu); + if (!is_valid_cluster(sbi, info->start_clu) && info->size) { + exfat_warn(sb, "start_clu is invalid cluster(0x%x)", + info->start_clu); + info->size = 0; + info->valid_size = 0; + } + + if (info->valid_size > info->size) { + exfat_warn(sb, "valid_size(%lld) is greater than size(%lld)", + info->valid_size, info->size); + info->valid_size = info->size; + } + if (info->size == 0) { info->flags = ALLOC_NO_FAT_CHAIN; info->start_clu = EXFAT_EOF_CLUSTER; - } else { + } else info->flags = ep2->dentry.stream.flags; - info->start_clu = - le32_to_cpu(ep2->dentry.stream.start_clu); - }
exfat_get_entry_time(sbi, &info->crtime, ep->dentry.file.create_tz,