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authorEric Biggers <ebiggers@google.com>2019-08-22 07:54:41 +0200
committerCasey Schaufler <casey@schaufler-ca.com>2019-09-04 18:37:07 +0200
commite5bfad3d7acc5702f32aafeb388362994f4d7bd0 (patch)
treec9daa0267c2dd110e5a8ccbed94ac8c8edb9c6e6 /security/smack
parentsecurity: smack: Fix possible null-pointer dereferences in smack_socket_sock_... (diff)
downloadlinux-e5bfad3d7acc5702f32aafeb388362994f4d7bd0.tar.xz
linux-e5bfad3d7acc5702f32aafeb388362994f4d7bd0.zip
smack: use GFP_NOFS while holding inode_smack::smk_lock
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>
Diffstat (limited to 'security/smack')
-rw-r--r--security/smack/smack_access.c6
-rw-r--r--security/smack/smack_lsm.c2
2 files changed, 4 insertions, 4 deletions
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index f1c93a7be9ec..38ac3da4e791 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -465,7 +465,7 @@ 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);
@@ -500,7 +500,7 @@ int smk_netlbl_mls(int level, char *catset, struct netlbl_lsm_secattr *sap,
if ((m & *cp) == 0)
continue;
rc = netlbl_catmap_setbit(&sap->attr.mls.cat,
- cat, GFP_KERNEL);
+ cat, GFP_NOFS);
if (rc < 0) {
netlbl_catmap_free(sap->attr.mls.cat);
return rc;
@@ -536,7 +536,7 @@ 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 516f7ba96f1e..abeb09c30633 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -288,7 +288,7 @@ static struct smack_known *smk_fetch(const char *name, struct inode *ip,
if (!(ip->i_opflags & IOP_XATTR))
return ERR_PTR(-EOPNOTSUPP);
- buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL);
+ buffer = kzalloc(SMK_LONGLABEL, GFP_NOFS);
if (buffer == NULL)
return ERR_PTR(-ENOMEM);