exec: CVE-2019-8980

exec: Fix mem leak in kernel_read_file

References:
https://nvd.nist.gov/vuln/detail/CVE-2019-8980
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=linux-4.9.y&id=dd6734e17903f16a47c78d0418f02e06df080c54

Change-Id: I13a751280f4ffe8391871a8ba25f0f266eb36b13
Signed-off-by: Andreas Wellving <andreas.wellving@enea.com>

2 files changed, 60 insertions, 0 deletions

diff --git a/patches/cve/4.9.x.scc b/patches/cve/4.9.x.scc
index 99eb8ce..3869cf7 100644
--- a/patches/cve/4.9.x.scc
+++ b/patches/cve/4.9.x.scc
@@ -34,3 +34,6 @@ patch CVE-2018-16884-sunrpc-use-after-free-in-svc_process_common.patch
 
 #CVEs fixed in 4.9.162:
 patch CVE-2019-9213-mm-enforce-min-addr-even-if-capable-in-expand_downwa.patch
+
+#CVEs fixed in 4.9.163:
+patch CVE-2019-8980-exec-Fix-mem-leak-in-kernel_read_file.patch
diff --git a/patches/cve/CVE-2019-8980-exec-Fix-mem-leak-in-kernel_read_file.patch b/patches/cve/CVE-2019-8980-exec-Fix-mem-leak-in-kernel_read_file.patch
new file mode 100644
index 0000000..8b3700b
--- /dev/null
+++ b/patches/cve/CVE-2019-8980-exec-Fix-mem-leak-in-kernel_read_file.patch
@@ -0,0 +1,57 @@
+From dd6734e17903f16a47c78d0418f02e06df080c54 Mon Sep 17 00:00:00 2001
+From: YueHaibing <yuehaibing@huawei.com>
+Date: Tue, 19 Feb 2019 10:10:38 +0800
+Subject: [PATCH] exec: Fix mem leak in kernel_read_file
+
+commit f612acfae86af7ecad754ae6a46019be9da05b8e upstream.
+
+syzkaller report this:
+BUG: memory leak
+unreferenced object 0xffffc9000488d000 (size 9195520):
+  comm "syz-executor.0", pid 2752, jiffies 4294787496 (age 18.757s)
+  hex dump (first 32 bytes):
+    ff ff ff ff ff ff ff ff a8 00 00 00 01 00 00 00  ................
+    02 00 00 00 00 00 00 00 80 a1 7a c1 ff ff ff ff  ..........z.....
+  backtrace:
+    [<000000000863775c>] __vmalloc_node mm/vmalloc.c:1795 [inline]
+    [<000000000863775c>] __vmalloc_node_flags mm/vmalloc.c:1809 [inline]
+    [<000000000863775c>] vmalloc+0x8c/0xb0 mm/vmalloc.c:1831
+    [<000000003f668111>] kernel_read_file+0x58f/0x7d0 fs/exec.c:924
+    [<000000002385813f>] kernel_read_file_from_fd+0x49/0x80 fs/exec.c:993
+    [<0000000011953ff1>] __do_sys_finit_module+0x13b/0x2a0 kernel/module.c:3895
+    [<000000006f58491f>] do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290
+    [<00000000ee78baf4>] entry_SYSCALL_64_after_hwframe+0x49/0xbe
+    [<00000000241f889b>] 0xffffffffffffffff
+
+It should goto 'out_free' lable to free allocated buf while kernel_read
+fails.
+
+CVE: CVE-2019-8980
+Upstream-Status: Backport [https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=linux-4.9.y&id=dd6734e17903f16a47c78d0418f02e06df080c54]
+
+Fixes: 39d637af5aa7 ("vfs: forbid write access when reading a file into memory")
+Signed-off-by: YueHaibing <yuehaibing@huawei.com>
+Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
+Cc: Thibaut Sautereau <thibaut@sautereau.fr>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Signed-off-by: Andreas Wellving <andreas.wellving@enea.com>
+---
+ fs/exec.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/fs/exec.c b/fs/exec.c
+index fcd8642ef2d2..81477116035d 100644
+--- a/fs/exec.c
++++ b/fs/exec.c
+@@ -938,7 +938,7 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size,
+                                    i_size - pos);
+                if (bytes < 0) {
+                        ret = bytes;
+-                       goto out;
++                       goto out_free;
+                }
+ 
+                if (bytes == 0)
+-- 
+2.20.1
+