| Message ID | 1532528839-20131-2-git-send-email-paolo.pisati@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | jfs: Fix inconsistency between memory allocation and ea_buf->max_size | expand |
On 25.07.2018 16:27, Paolo Pisati wrote: > From: Shankara Pailoor <shankarapailoor@gmail.com> > > CVE-2018-12233 > > The code is assuming the buffer is max_size length, but we weren't > allocating enough space for it. > > Signed-off-by: Shankara Pailoor <shankarapailoor@gmail.com> > Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com> > (cherry picked from commit 92d34134193e5b129dc24f8d79cb9196626e8d7a) > Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com> Acked-by: Stefan Bader <stefan.bader@canonical.com> > --- > fs/jfs/xattr.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/fs/jfs/xattr.c b/fs/jfs/xattr.c > index 6910662..54da0d6 100644 > --- a/fs/jfs/xattr.c > +++ b/fs/jfs/xattr.c > @@ -493,15 +493,17 @@ static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size) > if (size > PSIZE) { > /* > * To keep the rest of the code simple. Allocate a > - * contiguous buffer to work with > + * contiguous buffer to work with. Make the buffer large > + * enough to make use of the whole extent. > */ > - ea_buf->xattr = kmalloc(size, GFP_KERNEL); > + ea_buf->max_size = (size + sb->s_blocksize - 1) & > + ~(sb->s_blocksize - 1); > + > + ea_buf->xattr = kmalloc(ea_buf->max_size, GFP_KERNEL); > if (ea_buf->xattr == NULL) > return -ENOMEM; > > ea_buf->flag = EA_MALLOC; > - ea_buf->max_size = (size + sb->s_blocksize - 1) & > - ~(sb->s_blocksize - 1); > > if (ea_size == 0) > return 0; >
diff --git a/fs/jfs/xattr.c b/fs/jfs/xattr.c index 6910662..54da0d6 100644 --- a/fs/jfs/xattr.c +++ b/fs/jfs/xattr.c @@ -493,15 +493,17 @@ static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size) if (size > PSIZE) { /* * To keep the rest of the code simple. Allocate a - * contiguous buffer to work with + * contiguous buffer to work with. Make the buffer large + * enough to make use of the whole extent. */ - ea_buf->xattr = kmalloc(size, GFP_KERNEL); + ea_buf->max_size = (size + sb->s_blocksize - 1) & + ~(sb->s_blocksize - 1); + + ea_buf->xattr = kmalloc(ea_buf->max_size, GFP_KERNEL); if (ea_buf->xattr == NULL) return -ENOMEM; ea_buf->flag = EA_MALLOC; - ea_buf->max_size = (size + sb->s_blocksize - 1) & - ~(sb->s_blocksize - 1); if (ea_size == 0) return 0;