From ceffec5541cc22486d3ff492e3d76a33a68fbfa3 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Thu, 29 Mar 2012 16:19:05 +0900 Subject: [PATCH] gfp flags for security_inode_alloc()? 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 Signed-off-by: Casey Schaufler --- security/smack/smack_lsm.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index df45d3939188..5f80075d7713 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; @@ -563,7 +563,7 @@ 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; } @@ -586,7 +586,7 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir, issp->smk_flags |= SMK_INODE_CHANGED; } - *value = kstrdup(isp, GFP_KERNEL); + *value = kstrdup(isp, GFP_NOFS); if (*value == NULL) return -ENOMEM; } @@ -3426,7 +3426,7 @@ 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; }