On Tue, 2008-05-13 at 01:10 -0700, akpm@xxxxxxxxxxxxxxxxxxxx wrote:
> From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
>
> BUG: sleeping function called from invalid context at mm/slab.c:3052
> in_atomic():1, irqs_disabled():0
> 3 locks held by S99local/2391:
> #0: (&type->i_mutex_dir_key#4){--..}, at: [<c017973c>] do_lookup+0x72/0x146
> #1: (&isec->lock){--..}, at: [<c01cc3e5>] inode_doinit_with_dentry+0x35/0x52f
> #2: (policy_rwlock){..-?}, at: [<c01d7f89>] security_context_to_sid_core+0x5e/0x157
> Pid: 2391, comm: S99local Not tainted 2.6.26-rc2 #1
> [<c011863c>] __might_sleep+0xde/0xe5
> [<c01706e5>] __kmalloc+0x52/0xd5
> [<c01d7d9f>] string_to_context_struct+0x2e/0x1ba
> [<c01d7fa3>] security_context_to_sid_core+0x78/0x157
> [<c01d80a5>] security_context_to_sid_default+0x10/0x12
> [<c01cc609>] inode_doinit_with_dentry+0x259/0x52f
> [<c01cc8f1>] selinux_d_instantiate+0x12/0x14
Please use this patch instead.
Fix a sleeping function called from invalid context bug introduced by
the deferred mapping of contexts support, which restructured the code
into a helper and moved the locking to the caller. Always use GFP_ATOMIC
for allocating copies of the context and remove the gfp_flags argument as it
is no longer used. These allocations are generally small and transient.
Signed-off-by: Stephen Smalley <sds@xxxxxxxxxxxxx>
---
security/selinux/hooks.c | 3 +--
security/selinux/include/security.h | 2 +-
security/selinux/ss/services.c | 23 ++++++++++-------------
3 files changed, 12 insertions(+), 16 deletions(-)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 59c6e98..9684270 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1194,8 +1194,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
rc = 0;
} else {
rc = security_context_to_sid_default(context, rc, &sid,
- sbsec->def_sid,
- GFP_NOFS);
+ sbsec->def_sid);
if (rc) {
printk(KERN_WARNING "SELinux: %s: context_to_sid(%s) "
"returned %d for dev=%s ino=%ld\n",
diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
index 7c54300..e8e24a2 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -99,7 +99,7 @@ int security_context_to_sid(const char *scontext, u32 scontext_len,
u32 *out_sid);
int security_context_to_sid_default(const char *scontext, u32 scontext_len,
- u32 *out_sid, u32 def_sid, gfp_t gfp_flags);
+ u32 *out_sid, u32 def_sid);
int security_context_to_sid_force(const char *scontext, u32 scontext_len,
u32 *sid);
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index b86ac9d..498b084 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -735,8 +735,7 @@ static int string_to_context_struct(struct policydb *pol,
const char *scontext,
u32 scontext_len,
struct context *ctx,
- u32 def_sid,
- gfp_t gfp_flags)
+ u32 def_sid)
{
char *scontext2 = NULL;
struct role_datum *role;
@@ -748,7 +747,7 @@ static int string_to_context_struct(struct policydb *pol,
context_init(ctx);
/* Copy the string so that we can modify the copy as we parse it. */
- scontext2 = kmalloc(scontext_len+1, gfp_flags);
+ scontext2 = kmalloc(scontext_len+1, GFP_ATOMIC);
if (!scontext2) {
rc = -ENOMEM;
goto out;
@@ -827,8 +826,7 @@ out:
}
static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
- u32 *sid, u32 def_sid, gfp_t gfp_flags,
- int force)
+ u32 *sid, u32 def_sid, int force)
{
struct context context;
int rc = 0;
@@ -850,9 +848,9 @@ static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
POLICY_RDLOCK;
rc = string_to_context_struct(&policydb, &sidtab,
scontext, scontext_len,
- &context, def_sid, gfp_flags);
+ &context, def_sid);
if (rc == -EINVAL && force) {
- context.str = kmalloc(scontext_len+1, gfp_flags);
+ context.str = kmalloc(scontext_len+1, GFP_ATOMIC);
if (!context.str) {
rc = -ENOMEM;
goto out;
@@ -884,7 +882,7 @@ out:
int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
{
return security_context_to_sid_core(scontext, scontext_len,
- sid, SECSID_NULL, GFP_KERNEL, 0);
+ sid, SECSID_NULL, 0);
}
/**
@@ -906,17 +904,17 @@ int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
* memory is available, or 0 on success.
*/
int security_context_to_sid_default(const char *scontext, u32 scontext_len,
- u32 *sid, u32 def_sid, gfp_t gfp_flags)
+ u32 *sid, u32 def_sid)
{
return security_context_to_sid_core(scontext, scontext_len,
- sid, def_sid, gfp_flags, 1);
+ sid, def_sid, 1);
}
int security_context_to_sid_force(const char *scontext, u32 scontext_len,
u32 *sid)
{
return security_context_to_sid_core(scontext, scontext_len,
- sid, SECSID_NULL, GFP_KERNEL, 1);
+ sid, SECSID_NULL, 1);
}
static int compute_sid_handle_invalid_context(
@@ -1340,8 +1338,7 @@ static int convert_context(u32 key,
if (c->str) {
struct context ctx;
rc = string_to_context_struct(args->newp, NULL, c->str,
- c->len, &ctx, SECSID_NULL,
- GFP_KERNEL);
+ c->len, &ctx, SECSID_NULL);
if (!rc) {
printk(KERN_INFO
"SELinux: Context %s became valid (mapped).\n",
--
Stephen Smalley
National Security Agency
--
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