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authorEric Biggers <ebiggers@google.com>2019-08-21 22:54:41 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-10-07 21:01:07 +0200
commitac375073bb395750edd1652e420131acfc5b08d5 (patch)
treefcb61149bbef169538f0091acbd1016a4c29fb0c
parentcfaf71c99319a0ebec6f736ac5b400099257ae1b (diff)
smack: use GFP_NOFS while holding inode_smack::smk_lock
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>
-rw-r--r--security/smack/smack_access.c4
-rw-r--r--security/smack/smack_lsm.c2
2 files changed, 3 insertions, 3 deletions
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index a283f9e796c1..0df316c62005 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -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;
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 3055188729e6..716433e63052 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -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);