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Commit 497f3233 authored by Eric Paris's avatar Eric Paris Committed by Linus Torvalds
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IMA: use unsigned int instead of long for counters 



Currently IMA uses 2 longs in struct inode.  To save space (and as it
seems impossible to overflow 32 bits) we switch these to unsigned int.
The switch to unsigned does require slightly different checks for
underflow, but it isn't complex.

Signed-off-by: default avatarEric Paris <eparis@redhat.com>
Acked-by: default avatarMimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b575156d

security/integrity/ima/ima.h

+2 −2
Original line number Diff line number Diff line
@@ -106,8 +106,8 @@ struct ima_iint_cache { 
	unsigned long flags;

	u8 digest[IMA_DIGEST_SIZE];

	struct mutex mutex;	/* protects: version, flags, digest */

	long readcount;		/* measured files readcount */

	long writecount;	/* measured files writecount */

	unsigned int readcount;	/* measured files readcount */

	unsigned int writecount;/* measured files writecount */

	struct kref refcount;	/* ima_iint_cache reference count */

};

security/integrity/ima/ima_iint.c

+2 −2
Original line number Diff line number Diff line
@@ -125,12 +125,12 @@ void iint_free(struct kref *kref) 
	iint->version = 0;

	iint->flags = 0UL;

	if (iint->readcount != 0) {

		printk(KERN_INFO "%s: readcount: %ld\n", __func__,

		printk(KERN_INFO "%s: readcount: %u\n", __func__,

		       iint->readcount);

		iint->readcount = 0;

	}

	if (iint->writecount != 0) {

		printk(KERN_INFO "%s: writecount: %ld\n", __func__,

		printk(KERN_INFO "%s: writecount: %u\n", __func__,

		       iint->writecount);

		iint->writecount = 0;

	}

security/integrity/ima/ima_main.c

+10 −5
Original line number Diff line number Diff line
@@ -178,11 +178,18 @@ static void ima_dec_counts(struct ima_iint_cache *iint, struct inode *inode, 
			   struct file *file)

{

	mode_t mode = file->f_mode;

	bool dump = false;



	BUG_ON(!mutex_is_locked(&iint->mutex));



	if ((mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)

	if ((mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) {

		if (unlikely(iint->readcount == 0))

			dump = true;

		iint->readcount--;

	}

	if (mode & FMODE_WRITE) {

		if (unlikely(iint->writecount == 0))

			dump = true;

		iint->writecount--;

		if (iint->writecount == 0) {

			if (iint->version != inode->i_version)
@@ -190,10 +197,8 @@ static void ima_dec_counts(struct ima_iint_cache *iint, struct inode *inode, 
		}

	}



	if (((iint->readcount < 0) ||

	     (iint->writecount < 0)) &&

	    !ima_limit_imbalance(file)) {

		printk(KERN_INFO "%s: open/free imbalance (r:%ld w:%ld)\n",

	if (dump && !ima_limit_imbalance(file)) {

		printk(KERN_INFO "%s: open/free imbalance (r:%u w:%u)\n",

		       __func__, iint->readcount, iint->writecount);

		dump_stack();

	}