| Message ID | 1436227848-23827-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/fs/omfs/inode.c b/fs/omfs/inode.c index 70d4191..454111a 100644 --- a/fs/omfs/inode.c +++ b/fs/omfs/inode.c @@ -306,7 +306,8 @@ static const struct super_operations omfs_sops = { */ static int omfs_get_imap(struct super_block *sb) { - unsigned int bitmap_size, count, array_size; + unsigned int bitmap_size, array_size; + int count; struct omfs_sb_info *sbi = OMFS_SB(sb); struct buffer_head *bh; unsigned long **ptr;
This is a note to let you know that I have just added a patch titled omfs: fix sign confusion for bitmap loop counter to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue This patch is scheduled to be released in version 3.19.8-ckt3. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.19.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 5c3421a7fee42779c8607356fcbf79c93218bb80 Mon Sep 17 00:00:00 2001 From: Bob Copeland <me@bobcopeland.com> Date: Thu, 28 May 2015 15:44:35 -0700 Subject: omfs: fix sign confusion for bitmap loop counter commit c0345ee57d461343586b5e1e2f9c3c3766d07fe6 upstream. The count variable is used to iterate down to (below) zero from the size of the bitmap and handle the one-filling the remainder of the last partial bitmap block. The loop conditional expects count to be signed in order to detect when the final block is processed, after which count goes negative. Unfortunately, a recent change made this unsigned along with some other related fields. The result of is this is that during mount, omfs_get_imap will overrun the bitmap array and corrupt memory unless number of blocks happens to be a multiple of 8 * blocksize. Fix by changing count back to signed: it is guaranteed to fit in an s32 without overflow due to an enforced limit on the number of blocks in the filesystem. Signed-off-by: Bob Copeland <me@bobcopeland.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- fs/omfs/inode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) -- 1.9.1