* FAILED: patch "[PATCH] ovl: fix null pointer dereference in ovl_permission()" failed to apply to 6.1-stable tree
@ 2023-07-16 16:30 gregkh
2023-07-26 12:35 ` Miklos Szeredi
0 siblings, 1 reply; 3+ messages in thread
From: gregkh @ 2023-07-16 16:30 UTC (permalink / raw)
To: chengzhihao1, amir73il, brauner, mszeredi, stable; +Cc: stable
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 1a73f5b8f079fd42a544c1600beface50c63af7c
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2023071616-vastly-cognition-78ba@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
1a73f5b8f079 ("ovl: fix null pointer dereference in ovl_permission()")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 1a73f5b8f079fd42a544c1600beface50c63af7c Mon Sep 17 00:00:00 2001
From: Zhihao Cheng <chengzhihao1@huawei.com>
Date: Tue, 16 May 2023 22:16:18 +0800
Subject: [PATCH] ovl: fix null pointer dereference in ovl_permission()
Following process:
P1 P2
path_lookupat
link_path_walk
inode_permission
ovl_permission
ovl_i_path_real(inode, &realpath)
path->dentry = ovl_i_dentry_upper(inode)
drop_cache
__dentry_kill(ovl_dentry)
iput(ovl_inode)
ovl_destroy_inode(ovl_inode)
dput(oi->__upperdentry)
dentry_kill(upperdentry)
dentry_unlink_inode
upperdentry->d_inode = NULL
realinode = d_inode(realpath.dentry) // return NULL
inode_permission(realinode)
inode->i_sb // NULL pointer dereference
, will trigger an null pointer dereference at realinode:
[ 335.664979] BUG: kernel NULL pointer dereference,
address: 0000000000000002
[ 335.668032] CPU: 0 PID: 2592 Comm: ls Not tainted 6.3.0
[ 335.669956] RIP: 0010:inode_permission+0x33/0x2c0
[ 335.678939] Call Trace:
[ 335.679165] <TASK>
[ 335.679371] ovl_permission+0xde/0x320
[ 335.679723] inode_permission+0x15e/0x2c0
[ 335.680090] link_path_walk+0x115/0x550
[ 335.680771] path_lookupat.isra.0+0xb2/0x200
[ 335.681170] filename_lookup+0xda/0x240
[ 335.681922] vfs_statx+0xa6/0x1f0
[ 335.682233] vfs_fstatat+0x7b/0xb0
Fetch a reproducer in [Link].
Use the helper ovl_i_path_realinode() to get realinode and then do
non-nullptr checking.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217405
Fixes: 4b7791b2e958 ("ovl: handle idmappings in ovl_permission()")
Cc: <stable@vger.kernel.org> # v5.19
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Suggested-by: Christian Brauner <brauner@kernel.org>
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 541cf3717fc2..ca56b1328a2c 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -288,8 +288,8 @@ int ovl_permission(struct mnt_idmap *idmap,
int err;
/* Careful in RCU walk mode */
- ovl_i_path_real(inode, &realpath);
- if (!realpath.dentry) {
+ realinode = ovl_i_path_real(inode, &realpath);
+ if (!realinode) {
WARN_ON(!(mask & MAY_NOT_BLOCK));
return -ECHILD;
}
@@ -302,7 +302,6 @@ int ovl_permission(struct mnt_idmap *idmap,
if (err)
return err;
- realinode = d_inode(realpath.dentry);
old_cred = ovl_override_creds(inode->i_sb);
if (!upperinode &&
!special_file(realinode->i_mode) && mask & MAY_WRITE) {
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: FAILED: patch "[PATCH] ovl: fix null pointer dereference in ovl_permission()" failed to apply to 6.1-stable tree
2023-07-16 16:30 FAILED: patch "[PATCH] ovl: fix null pointer dereference in ovl_permission()" failed to apply to 6.1-stable tree gregkh
@ 2023-07-26 12:35 ` Miklos Szeredi
2023-07-27 10:57 ` Greg KH
0 siblings, 1 reply; 3+ messages in thread
From: Miklos Szeredi @ 2023-07-26 12:35 UTC (permalink / raw)
To: gregkh; +Cc: chengzhihao1, amir73il, brauner, stable
On Sun, Jul 16, 2023 at 6:30 PM <gregkh@linuxfoundation.org> wrote:
>
>
> The patch below does not apply to the 6.1-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.
>
> To reproduce the conflict and resubmit, you may use the following commands:
>
> git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
> git checkout FETCH_HEAD
> git cherry-pick -x 1a73f5b8f079fd42a544c1600beface50c63af7c
Applies and tests cleanly against v6.1.41.
Maybe the failure was due to dependency on commit b2dd05f107b1 ("ovl:
let helper ovl_i_path_real() return the realinode")?
Thanks,
Miklos
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: FAILED: patch "[PATCH] ovl: fix null pointer dereference in ovl_permission()" failed to apply to 6.1-stable tree
2023-07-26 12:35 ` Miklos Szeredi
@ 2023-07-27 10:57 ` Greg KH
0 siblings, 0 replies; 3+ messages in thread
From: Greg KH @ 2023-07-27 10:57 UTC (permalink / raw)
To: Miklos Szeredi; +Cc: chengzhihao1, amir73il, brauner, stable
On Wed, Jul 26, 2023 at 02:35:38PM +0200, Miklos Szeredi wrote:
> On Sun, Jul 16, 2023 at 6:30 PM <gregkh@linuxfoundation.org> wrote:
> >
> >
> > The patch below does not apply to the 6.1-stable tree.
> > If someone wants it applied there, or to any other stable or longterm
> > tree, then please email the backport, including the original git commit
> > id to <stable@vger.kernel.org>.
> >
> > To reproduce the conflict and resubmit, you may use the following commands:
> >
> > git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
> > git checkout FETCH_HEAD
> > git cherry-pick -x 1a73f5b8f079fd42a544c1600beface50c63af7c
>
> Applies and tests cleanly against v6.1.41.
>
> Maybe the failure was due to dependency on commit b2dd05f107b1 ("ovl:
> let helper ovl_i_path_real() return the realinode")?
Odd, maybe? I've queued this up now, thanks.
greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2023-07-27 10:58 UTC | newest]
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2023-07-16 16:30 FAILED: patch "[PATCH] ovl: fix null pointer dereference in ovl_permission()" failed to apply to 6.1-stable tree gregkh
2023-07-26 12:35 ` Miklos Szeredi
2023-07-27 10:57 ` Greg KH
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