[PATCH] BSD Secure Levels: memory alloc failure check, 2.6.11-rc2-mm1 (4/8)

[Michael Halcrow]

This is the fourth in a series of eight patches to the BSD Secure
Levels LSM.  It adds a check for a memory allocation failure
condition.  Thanks to Vesa-Matti J Kari for pointing out this problem.

Signed off by: Michael Halcrow <[EMAIL PROTECTED]>

Index: linux-2.6.11-rc2-mm1-modules/security/seclvl.c
===================================================================
--- linux-2.6.11-rc2-mm1-modules.orig/security/seclvl.c 2005-02-03 
15:37:26.231252048 -0600
+++ linux-2.6.11-rc2-mm1-modules/security/seclvl.c      2005-02-03 
15:39:35.786556648 -0600
@@ -310,7 +310,7 @@
 static int
 plaintext_to_sha1(unsigned char *hash, const char *plaintext, int len)
 {
-       char *pgVirtAddr;
+       char *pg_virt_addr;
        struct crypto_tfm *tfm;
        struct scatterlist sg[1];
        if (len > PAGE_SIZE) {
@@ -327,16 +327,20 @@
        }
        // Just get a new page; don't play around with page boundaries
        // and scatterlists.
-       pgVirtAddr = (char *)__get_free_page(GFP_KERNEL);
-       sg[0].page = virt_to_page(pgVirtAddr);
+       pg_virt_addr = (char *)__get_free_page(GFP_KERNEL);
+       if (!pg_virt_addr) {
+               seclvl_printk(0, KERN_ERR "%s: Out of memory\n", __FUNCTION__);
+               return -ENOMEM;
+       }       
+       sg[0].page = virt_to_page(pg_virt_addr);
        sg[0].offset = 0;
        sg[0].length = len;
-       strncpy(pgVirtAddr, plaintext, len);
+       strncpy(pg_virt_addr, plaintext, len);
        crypto_digest_init(tfm);
        crypto_digest_update(tfm, sg, 1);
        crypto_digest_final(tfm, hash);
        crypto_free_tfm(tfm);
-       free_page((unsigned long)pgVirtAddr);
+       free_page((unsigned long)pg_virt_addr);
        return 0;
 }