| Message ID | 20210806095820.83731-3-lczerner@redhat.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [1/7] e2fsck: value stored to err is never read | expand |
On Fri, Aug 06, 2021 at 11:58:16AM +0200, Lukas Czerner wrote: > The ext2fs_check_mount_point() function can be called with mtpt being > NULL as for example from ext2fs_check_if_mounted(). However in the > is_swap_device condition we use the mtpt in strncpy without checking > whether it is non-null first. > > This should not be a problem on linux since the previous attempt to open > the device exclusively would have prevented us from ever reaching the > problematic strncpy. However it's still a bug and can cause problems on > other systems, fix it by conditioning strncpy on mtpt not being null. > > Signed-off-by: Lukas Czerner <lczerner@redhat.com> Applied, thanks. - Ted
diff --git a/lib/ext2fs/ismounted.c b/lib/ext2fs/ismounted.c index c9e6a9d0..aee7d726 100644 --- a/lib/ext2fs/ismounted.c +++ b/lib/ext2fs/ismounted.c @@ -393,7 +393,8 @@ errcode_t ext2fs_check_mount_point(const char *device, int *mount_flags, if (is_swap_device(device)) { *mount_flags = EXT2_MF_MOUNTED | EXT2_MF_SWAP; - strncpy(mtpt, "<swap>", mtlen); + if (mtpt) + strncpy(mtpt, "<swap>", mtlen); } else { #ifdef HAVE_SETMNTENT retval = check_mntent(device, mount_flags, mtpt, mtlen);
The ext2fs_check_mount_point() function can be called with mtpt being NULL as for example from ext2fs_check_if_mounted(). However in the is_swap_device condition we use the mtpt in strncpy without checking whether it is non-null first. This should not be a problem on linux since the previous attempt to open the device exclusively would have prevented us from ever reaching the problematic strncpy. However it's still a bug and can cause problems on other systems, fix it by conditioning strncpy on mtpt not being null. Signed-off-by: Lukas Czerner <lczerner@redhat.com> --- lib/ext2fs/ismounted.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)