From: Greg Kroah-Hartman Date: Tue, 16 Jun 2020 07:52:29 +0000 (+0200) Subject: 4.4-stable patches X-Git-Tag: v5.4.47~57 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a013f42b1579844d5e6770a18f8225e6ca66aa67;p=thirdparty%2Fkernel%2Fstable-queue.git 4.4-stable patches added patches: ovl-initialize-error-in-ovl_copy_xattr.patch proc-use-new_inode-not-new_inode_pseudo.patch --- diff --git a/queue-4.4/ovl-initialize-error-in-ovl_copy_xattr.patch b/queue-4.4/ovl-initialize-error-in-ovl_copy_xattr.patch new file mode 100644 index 00000000000..2820faa529f --- /dev/null +++ b/queue-4.4/ovl-initialize-error-in-ovl_copy_xattr.patch @@ -0,0 +1,46 @@ +From 520da69d265a91c6536c63851cbb8a53946974f0 Mon Sep 17 00:00:00 2001 +From: Yuxuan Shui +Date: Wed, 27 May 2020 04:08:02 +0100 +Subject: ovl: initialize error in ovl_copy_xattr + +From: Yuxuan Shui + +commit 520da69d265a91c6536c63851cbb8a53946974f0 upstream. + +In ovl_copy_xattr, if all the xattrs to be copied are overlayfs private +xattrs, the copy loop will terminate without assigning anything to the +error variable, thus returning an uninitialized value. + +If ovl_copy_xattr is called from ovl_clear_empty, this uninitialized error +value is put into a pointer by ERR_PTR(), causing potential invalid memory +accesses down the line. + +This commit initialize error with 0. This is the correct value because when +there's no xattr to copy, because all xattrs are private, ovl_copy_xattr +should succeed. + +This bug is discovered with the help of INIT_STACK_ALL and clang. + +Signed-off-by: Yuxuan Shui +Link: https://bugs.chromium.org/p/chromium/issues/detail?id=1050405 +Fixes: 0956254a2d5b ("ovl: don't copy up opaqueness") +Cc: stable@vger.kernel.org # v4.8 +Signed-off-by: Alexander Potapenko +Signed-off-by: Miklos Szeredi +Signed-off-by: Greg Kroah-Hartman + +--- + fs/overlayfs/copy_up.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +--- a/fs/overlayfs/copy_up.c ++++ b/fs/overlayfs/copy_up.c +@@ -24,7 +24,7 @@ int ovl_copy_xattr(struct dentry *old, s + { + ssize_t list_size, size, value_size = 0; + char *buf, *name, *value = NULL; +- int uninitialized_var(error); ++ int error = 0; + size_t slen; + + if (!old->d_inode->i_op->getxattr || diff --git a/queue-4.4/proc-use-new_inode-not-new_inode_pseudo.patch b/queue-4.4/proc-use-new_inode-not-new_inode_pseudo.patch new file mode 100644 index 00000000000..4222a6a83b7 --- /dev/null +++ b/queue-4.4/proc-use-new_inode-not-new_inode_pseudo.patch @@ -0,0 +1,83 @@ +From ef1548adada51a2f32ed7faef50aa465e1b4c5da Mon Sep 17 00:00:00 2001 +From: "Eric W. Biederman" +Date: Fri, 12 Jun 2020 09:42:03 -0500 +Subject: proc: Use new_inode not new_inode_pseudo + +From: Eric W. Biederman + +commit ef1548adada51a2f32ed7faef50aa465e1b4c5da upstream. + +Recently syzbot reported that unmounting proc when there is an ongoing +inotify watch on the root directory of proc could result in a use +after free when the watch is removed after the unmount of proc +when the watcher exits. + +Commit 69879c01a0c3 ("proc: Remove the now unnecessary internal mount +of proc") made it easier to unmount proc and allowed syzbot to see the +problem, but looking at the code it has been around for a long time. + +Looking at the code the fsnotify watch should have been removed by +fsnotify_sb_delete in generic_shutdown_super. Unfortunately the inode +was allocated with new_inode_pseudo instead of new_inode so the inode +was not on the sb->s_inodes list. Which prevented +fsnotify_unmount_inodes from finding the inode and removing the watch +as well as made it so the "VFS: Busy inodes after unmount" warning +could not find the inodes to warn about them. + +Make all of the inodes in proc visible to generic_shutdown_super, +and fsnotify_sb_delete by using new_inode instead of new_inode_pseudo. +The only functional difference is that new_inode places the inodes +on the sb->s_inodes list. + +I wrote a small test program and I can verify that without changes it +can trigger this issue, and by replacing new_inode_pseudo with +new_inode the issues goes away. + +Cc: stable@vger.kernel.org +Link: https://lkml.kernel.org/r/000000000000d788c905a7dfa3f4@google.com +Reported-by: syzbot+7d2debdcdb3cb93c1e5e@syzkaller.appspotmail.com +Fixes: 0097875bd415 ("proc: Implement /proc/thread-self to point at the directory of the current thread") +Fixes: 021ada7dff22 ("procfs: switch /proc/self away from proc_dir_entry") +Fixes: 51f0885e5415 ("vfs,proc: guarantee unique inodes in /proc") +Signed-off-by: "Eric W. Biederman" +Signed-off-by: Greg Kroah-Hartman + +--- + fs/proc/inode.c | 2 +- + fs/proc/self.c | 2 +- + fs/proc/thread_self.c | 2 +- + 3 files changed, 3 insertions(+), 3 deletions(-) + +--- a/fs/proc/inode.c ++++ b/fs/proc/inode.c +@@ -415,7 +415,7 @@ const struct inode_operations proc_link_ + + struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de) + { +- struct inode *inode = new_inode_pseudo(sb); ++ struct inode *inode = new_inode(sb); + + if (inode) { + inode->i_ino = de->low_ino; +--- a/fs/proc/self.c ++++ b/fs/proc/self.c +@@ -51,7 +51,7 @@ int proc_setup_self(struct super_block * + mutex_lock(&root_inode->i_mutex); + self = d_alloc_name(s->s_root, "self"); + if (self) { +- struct inode *inode = new_inode_pseudo(s); ++ struct inode *inode = new_inode(s); + if (inode) { + inode->i_ino = self_inum; + inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; +--- a/fs/proc/thread_self.c ++++ b/fs/proc/thread_self.c +@@ -52,7 +52,7 @@ int proc_setup_thread_self(struct super_ + mutex_lock(&root_inode->i_mutex); + thread_self = d_alloc_name(s->s_root, "thread-self"); + if (thread_self) { +- struct inode *inode = new_inode_pseudo(s); ++ struct inode *inode = new_inode(s); + if (inode) { + inode->i_ino = thread_self_inum; + inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; diff --git a/queue-4.4/series b/queue-4.4/series index bf7652fb176..da91c57d14b 100644 --- a/queue-4.4/series +++ b/queue-4.4/series @@ -29,3 +29,5 @@ spi-no-need-to-assign-dummy-value-in-spi_unregister_.patch spi-fix-controller-unregister-order.patch spi-pxa2xx-fix-controller-unregister-order.patch spi-bcm2835-fix-controller-unregister-order.patch +ovl-initialize-error-in-ovl_copy_xattr.patch +proc-use-new_inode-not-new_inode_pseudo.patch