staging: exfat: check for null return from call to FAT_getblk

A call to FAT_getblk is missing a null return check which can
lead to a null pointer dereference.  Fix this by adding a null
check to match all the other FAT_getblk return sanity checks.

Addresses-Coverity: ("Dereference null return")
Fixes: c48c9f7ff3 ("staging: exfat: add exfat filesystem code to staging")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20190830175050.12706-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Colin Ian King 2019-08-30 18:50:50 +01:00 committed by Greg Kroah-Hartman
parent 329101244f
commit dab8fe7ea2
1 changed files with 2 additions and 0 deletions

View File

@ -369,6 +369,8 @@ static s32 __FAT_write(struct super_block *sb, u32 loc, u32 content)
FAT_modify(sb, sec);
fat_sector = FAT_getblk(sb, ++sec);
if (!fat_sector)
return -1;
fat_sector[0] = (u8)((fat_sector[0] & 0xF0) |
(content >> 8));
} else {