a7y18lte-ubports/android_kernel_samsung_a7y18lte
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

smack: use GFP_NOFS while holding inode_smack::smk_lock

Browse Source 
commit e5bfad3d7acc5702f32aafeb388362994f4d7bd0 upstream.

inode_smack::smk_lock is taken during smack_d_instantiate(), which is
called during a filesystem transaction when creating a file on ext4.
Therefore to avoid a deadlock, all code that takes this lock must use
GFP_NOFS, to prevent memory reclaim from waiting for the filesystem
transaction to complete.

Reported-by: syzbot+0eefc1e06a77d327a056@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Eric Biggers 2019-08-21 22:54:41 -07:00 committed by prashantpaddune
parent 3ebea9391a
commit 1cacc84790
2 changed files with 3 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
security/smack/smack_access.c
View File

@ -474,7 +474,7 @@ char *smk_parse_smack(const char *string, int len)
if (i == 0 || i >= SMK_LONGLABEL)
return ERR_PTR(-EINVAL);
smack = kzalloc(i + 1, GFP_KERNEL);
smack = kzalloc(i + 1, GFP_NOFS);
if (smack == NULL)
return ERR_PTR(-ENOMEM);
@ -545,7 +545,7 @@ struct smack_known *smk_import_entry(const char *string, int len)
if (skp != NULL)
goto freeout;
skp = kzalloc(sizeof(*skp), GFP_KERNEL);
skp = kzalloc(sizeof(*skp), GFP_NOFS);
if (skp == NULL) {
skp = ERR_PTR(-ENOMEM);
goto freeout;

2
security/smack/smack_lsm.c
View File

@ -268,7 +268,7 @@ static struct smack_known *smk_fetch(const char *name, struct inode *ip,
if (ip->i_op->getxattr == NULL)
return ERR_PTR(-EOPNOTSUPP);
buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL);
buffer = kzalloc(SMK_LONGLABEL, GFP_NOFS);
if (buffer == NULL)
return ERR_PTR(-ENOMEM);