[PATCH 4/4] fs: ext4: preventing integer overflow in ext4fs_get_bgdtable()

[Timo tp Preißl]

Signed-off-by: Timo tp Preißl <t.prei...@proton.me>
---
 fs/ext4/ext4_write.c | 7 ++++++-
 fs/fs.c              | 2 +-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/ext4_write.c b/fs/ext4/ext4_write.c
index 5b290f0d80d..02cf9cf0cc3 100644
--- a/fs/ext4/ext4_write.c
+++ b/fs/ext4/ext4_write.c
@@ -108,7 +108,12 @@ int ext4fs_get_bgdtable(void)
 {
        int status;
        struct ext_filesystem *fs = get_fs();
-       int gdsize_total = ROUND(fs->no_blkgrp * fs->gdsize, fs->blksz);
+       size_t alloc;
+
+       if (__builtin_mul_overflow(fs->no_blkgrp ,fs->gdsize, &alloc))
+               return -1;
+
+       size_t gdsize_total = ROUND(alloc, fs->blksz);
        fs->no_blk_pergdt = gdsize_total / fs->blksz;
 
        /* allocate memory for gdtable */
diff --git a/fs/fs.c b/fs/fs.c
index efcf94caa1b..f22b75573b9 100644
--- a/fs/fs.c
+++ b/fs/fs.c
@@ -1071,7 +1071,7 @@ int do_mv(struct cmd_tbl *cmdtp, int flag, int argc, char 
*const argv[],
 
                if (__builtin_add_overflow(dst_len, src_len, &total) ||
                        __builtin_add_overflow(total, 2, &total)) {
-               return 0;
+                       return 0;
                }
 
                new_dst = calloc(1, total);
-- 
2.43.0