From: Yuezhang Mo Yuezhang.Mo@sony.com
mainline inclusion from mainline-v6.10-rc2 commit 184fa506e392eb78364d9283c961217ff2c0617b category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBDHGB CVE: CVE-2024-53147
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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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
Conflicts: fs/exfat/namei.c [Conflicts due to not merge 11a347fb6cef ("exfat: change to get file size from DataLength")] Signed-off-by: Long Li leo.lilong@huawei.com --- fs/exfat/namei.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/fs/exfat/namei.c b/fs/exfat/namei.c index d62d961e278d..5b78b9ba417e 100644 --- a/fs/exfat/namei.c +++ b/fs/exfat/namei.c @@ -655,13 +655,19 @@ static int exfat_find(struct inode *dir, struct qstr *qname, info->type = exfat_get_entry_type(ep); info->attr = le16_to_cpu(ep->dentry.file.attr); info->size = le64_to_cpu(ep2->dentry.stream.valid_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; + } + if (info->size == 0) { info->flags = ALLOC_NO_FAT_CHAIN; info->start_clu = EXFAT_EOF_CLUSTER; } 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,