Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 18/20] ext4/fscrypto: avoid RCU lookup in d_revalidate | Date | Fri, 5 May 2017 11:33:08 -0700 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Jaegeuk Kim <jaegeuk@kernel.org>
commit 03a8bb0e53d9562276045bdfcf2b5de2e4cff5a1 upstream.
As Al pointed, d_revalidate should return RCU lookup before using d_inode. This was originally introduced by: commit 34286d666230 ("fs: rcu-walk aware d_revalidate method").
Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- fs/ext4/crypto.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/fs/ext4/crypto.c +++ b/fs/ext4/crypto.c @@ -34,6 +34,7 @@ #include <linux/random.h> #include <linux/scatterlist.h> #include <linux/spinlock_types.h> +#include <linux/namei.h> #include "ext4_extents.h" #include "xattr.h" @@ -481,6 +482,9 @@ static int ext4_d_revalidate(struct dent struct ext4_crypt_info *ci; int dir_has_key, cached_with_key; + if (flags & LOOKUP_RCU) + return -ECHILD; + dir = dget_parent(dentry); if (!ext4_encrypted_inode(d_inode(dir))) { dput(dir);
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