[PATCH] add kmalloc checking to fs/jffs/intrep.c (245-ac16)

From: Rasmus Andersen (rasmus@jaquet.dk)
Date: Sat Jun 23 2001 - 09:42:18 EST

Hi.

The following patch adds some checks for kmalloc returning NULL
to fs/jffs/intrep.c along with some way of getting that propagated
back. Applies against 245ac16 and 246p5. These dereferences were
reported by the Stanford team a way back.

--- linux-245-ac16-clean/fs/jffs/intrep.c Thu Jun 21 21:26:24 2001
+++ linux-245-ac16/fs/jffs/intrep.c Sat Jun 23 16:25:33 2001
@@ -320,8 +320,8 @@
 }
 
 
-__u32
-jffs_checksum_flash(struct mtd_info *mtd, loff_t start, int size)
+int
+jffs_checksum_flash(struct mtd_info *mtd, loff_t start, int size, __u32* checksum)
 {
         __u32 sum = 0;
         loff_t ptr = start;
@@ -330,6 +330,10 @@
 
         /* Allocate read buffer */
         read_buf = (__u8 *) kmalloc (sizeof(__u8) * 4096, GFP_KERNEL);
+ if (!read_buf) {
+ printk(KERN_ERR "(jffs:) Out of memory allocating buffer. Aborting.");
+ return -1;
+ }
 
         /* Loop until checksum done */
         while (size) {
@@ -357,7 +361,8 @@
 
         /* Return result */
         D3(printk("checksum result: 0x%08x\n", sum));
- return sum;
+ *checksum = sum;
+ return 0;
 }
 static __inline__ void jffs_fm_write_lock(struct jffs_fmcontrol *fmc)
 {
@@ -605,6 +610,8 @@
 
         /* Allocate read buffer */
         read_buf = (__u8 *) kmalloc (sizeof(__u8) * 4096, GFP_KERNEL);
+ if (!read_buf)
+ return -ENOMEM;
 
         /* Start the scan. */
         while (pos < end) {
@@ -859,7 +866,10 @@
                         if (raw_inode.rename) {
                                 deleted_file = flash_read_u32(fmc->mtd, pos);
                         }
- checksum = jffs_checksum_flash(fmc->mtd, pos, raw_inode.dsize);
+ if (jffs_checksum_flash(fmc->mtd, pos,
+ raw_inode.dsize, &checksum))
+ return -ENOMEM;
+
                         pos += raw_inode.dsize
                                + JFFS_GET_PAD_BYTES(raw_inode.dsize);
  

-- 
Regards,
        Rasmus(rasmus@jaquet.dk)

Television is called a medium because it is neither rare nor well-done. 
  -- Anonymous
-
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This archive was generated by hypermail 2b29 : Sat Jun 23 2001 - 21:00:42 EST