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ext2fs: Fix old out-of-bounds access.

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Overrunning buffer pointed to by (caddr_t)&oip->i_db[0] of 48 bytes by
passing it to a function which accesses it at byte offset 59 using
argument 60UL.

The issue was inherited from an older FFS implementation and
fixed there with by merging UFS2 in r98542. We follow the
FFS fix.

Discussed with:	bde
CID:		1007665
MFC after:	3 days
This commit is contained in:
Pedro F. Giffuni 2014-12-09 14:56:00 +00:00
parent 469cb95ad6
commit 8f87059b41
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=275645
1 changed files with 16 additions and 6 deletions
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22
sys/fs/ext2fs/ext2_inode.c
View file

@ -224,14 +224,18 @@ ext2_truncate(struct vnode *vp, off_t length, int flags, struct ucred *cred,
* will be returned to the free list. lastiblock values are also
* normalized to -1 for calls to ext2_indirtrunc below.
*/
bcopy((caddr_t)&oip->i_db[0], (caddr_t)oldblks, sizeof(oldblks));
for (level = TRIPLE; level >= SINGLE; level--)
for (level = TRIPLE; level >= SINGLE; level--) {
oldblks[NDADDR + level] = oip->i_ib[level];
if (lastiblock[level] < 0) {
oip->i_ib[level] = 0;
lastiblock[level] = -1;
}
for (i = NDADDR - 1; i > lastblock; i--)
oip->i_db[i] = 0;
}
for (i = 0; i < NDADDR; i++) {
oldblks[i] = oip->i_db[i];
if (i > lastblock)
oip->i_db[i] = 0;
}
oip->i_flag |= IN_CHANGE | IN_UPDATE;
allerror = ext2_update(ovp, !DOINGASYNC(ovp));
@ -241,8 +245,14 @@ ext2_truncate(struct vnode *vp, off_t length, int flags, struct ucred *cred,
* Note that we save the new block configuration so we can check it
* when we are done.
*/
bcopy((caddr_t)&oip->i_db[0], (caddr_t)newblks, sizeof(newblks));
bcopy((caddr_t)oldblks, (caddr_t)&oip->i_db[0], sizeof(oldblks));
for (i = 0; i < NDADDR; i++) {
newblks[i] = oip->i_db[i];
oip->i_db[i] = oldblks[i];
}
for (i = 0; i < NIADDR; i++) {
newblks[NDADDR + i] = oip->i_ib[i];
oip->i_ib[i] = oldblks[NDADDR + i];
}
oip->i_size = osize;
error = vtruncbuf(ovp, cred, length, (int)fs->e2fs_bsize);
if (error && (allerror == 0))