[kernel/f20] CVE-2014-XXXX isofs: infinite loop in CE record entries (rhbz 1175235 1175250)

[Josh Boyer]

commit 910d932b3ccaab891e4ce5a5e2f2259f5b7eaafd
Author: Josh Boyer <jwboyer at fedoraproject.org>
Date:   Wed Dec 17 08:29:30 2014 -0500

    CVE-2014-XXXX isofs: infinite loop in CE record entries (rhbz 1175235 1175250)

 isofs-Fix-infinite-looping-over-CE-entries.patch |   54 ++++++++++++++++++++++
 kernel.spec                                      |    9 ++++
 2 files changed, 63 insertions(+), 0 deletions(-)
---
diff --git a/isofs-Fix-infinite-looping-over-CE-entries.patch b/isofs-Fix-infinite-looping-over-CE-entries.patch
new file mode 100644
index 0000000..bff25ac
--- /dev/null
+++ b/isofs-Fix-infinite-looping-over-CE-entries.patch
@@ -0,0 +1,54 @@
+From: Jan Kara <jack at suse.cz>
+Date: Mon, 15 Dec 2014 14:22:46 +0100
+Subject: [PATCH] isofs: Fix infinite looping over CE entries
+
+Rock Ridge extensions define so called Continuation Entries (CE) which
+define where is further space with Rock Ridge data. Corrupted isofs
+image can contain arbitrarily long chain of these, including a one
+containing loop and thus causing kernel to end in an infinite loop when
+traversing these entries.
+
+Limit the traversal to 32 entries which should be more than enough space
+to store all the Rock Ridge data.
+
+Reported-by: P J P <ppandit at redhat.com>
+CC: stable at vger.kernel.org
+Signed-off-by: Jan Kara <jack at suse.cz>
+---
+ fs/isofs/rock.c | 6 ++++++
+ 1 file changed, 6 insertions(+)
+
+diff --git a/fs/isofs/rock.c b/fs/isofs/rock.c
+index f488bbae541a..bb63254ed848 100644
+--- a/fs/isofs/rock.c
++++ b/fs/isofs/rock.c
+@@ -30,6 +30,7 @@ struct rock_state {
+ 	int cont_size;
+ 	int cont_extent;
+ 	int cont_offset;
++	int cont_loops;
+ 	struct inode *inode;
+ };
+ 
+@@ -73,6 +74,9 @@ static void init_rock_state(struct rock_state *rs, struct inode *inode)
+ 	rs->inode = inode;
+ }
+ 
++/* Maximum number of Rock Ridge continuation entries */
++#define RR_MAX_CE_ENTRIES 32
++
+ /*
+  * Returns 0 if the caller should continue scanning, 1 if the scan must end
+  * and -ve on error.
+@@ -105,6 +109,8 @@ static int rock_continue(struct rock_state *rs)
+ 			goto out;
+ 		}
+ 		ret = -EIO;
++		if (++rs->cont_loops >= RR_MAX_CE_ENTRIES)
++			goto out;
+ 		bh = sb_bread(rs->inode->i_sb, rs->cont_extent);
+ 		if (bh) {
+ 			memcpy(rs->buffer, bh->b_data + rs->cont_offset,
+-- 
+2.1.0
+
diff --git a/kernel.spec b/kernel.spec
index 80652c8..07dbfc3 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -759,6 +759,9 @@ Patch26101: powerpc-powernv-force-all-CPUs-to-be-bootable.patch
 Patch26098: move-d_rcu-from-overlapping-d_child-to-overlapping-d.patch
 Patch26099: deal-with-deadlock-in-d_walk.patch
 
+#CVE-2014-XXXX rhbz 1175235 1175250
+Patch26102: isofs-Fix-infinite-looping-over-CE-entries.patch
+
 # git clone ssh://git.fedorahosted.org/git/kernel-arm64.git, git diff master...devel
 Patch30000: kernel-arm64.patch
 
@@ -1488,6 +1491,9 @@ ApplyPatch powerpc-powernv-force-all-CPUs-to-be-bootable.patch
 ApplyPatch move-d_rcu-from-overlapping-d_child-to-overlapping-d.patch
 ApplyPatch deal-with-deadlock-in-d_walk.patch
 
+#CVE-2014-XXXX rhbz 1175235 1175250
+ApplyPatch isofs-Fix-infinite-looping-over-CE-entries.patch
+
 %if 0%{?aarch64patches}
 ApplyPatch kernel-arm64.patch
 %ifnarch aarch64 # this is stupid, but i want to notice before secondary koji does.
@@ -2306,6 +2312,9 @@ fi
 #                 ||----w |
 #                 ||     ||
 %changelog
+* Wed Dec 17 2014 Josh Boyer <jwboyer at fedoraproject.org>
+- CVE-2014-XXXX isofs: infinite loop in CE record entries (rhbz 1175235 1175250)
+
 * Tue Dec 16 2014 Justin M. Forbes <jforbes at fedoraproject.org> - 3.17.7-200
 - Linux v3.17.7