Dave Chinner wrote:
> Yes, because you have no idea what the calling context is except
> for the fact that is from somewhere inside filesystem code and the
> filesystem could be holding locks. Therefore, GFP_NOFS is really the
> only really safe way to allocate memory here.
I see. Thank you.
I'm not sure, but can call trace happen where somewhere inside network
filesystem or stackable filesystem code with locks held invokes operations that
involves GFP_KENREL memory allocation outside that filesystem?
----------
[PATCH] SMACK: Fix incorrect GFP_KERNEL usage.
new_inode_smack() which can be called from smack_inode_alloc_security() needs
to use GFP_NOFS like SELinux's inode_alloc_security() does, for
security_inode_alloc() is called from inode_init_always() and
inode_init_always() is called from xfs_inode_alloc() which is using GFP_NOFS.
smack_inode_init_security() needs to use GFP_NOFS like
selinux_inode_init_security() does, for initxattrs() callback function (e.g.
btrfs_initxattrs()) which is called from security_inode_init_security() is
using GFP_NOFS.
smack_audit_rule_match() needs to use GFP_ATOMIC, for
security_audit_rule_match() can be called from audit_filter_user_rules() and
audit_filter_user_rules() is called from audit_filter_user() with RCU read lock
held.
Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index cd667b4..697cf85 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -79,7 +79,7 @@ struct inode_smack *new_inode_smack(char *smack)
{
struct inode_smack *isp;
- isp = kzalloc(sizeof(struct inode_smack), GFP_KERNEL);
+ isp = kzalloc(sizeof(struct inode_smack), GFP_NOFS);
if (isp == NULL)
return NULL;
@@ -562,7 +562,7 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
int may;
if (name) {
- *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL);
+ *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_NOFS);
if (*name == NULL)
return -ENOMEM;
}
@@ -582,7 +582,7 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
smk_inode_transmutable(dir))
isp = dsp;
- *value = kstrdup(isp, GFP_KERNEL);
+ *value = kstrdup(isp, GFP_NOFS);
if (*value == NULL)
return -ENOMEM;
}
@@ -3384,7 +3384,7 @@ static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
char *rule = vrule;
if (!rule) {
- audit_log(actx, GFP_KERNEL, AUDIT_SELINUX_ERR,
+ audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
"Smack: missing rule\n");
return -ENOENT;
}
--
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