Eric Lee / smarc-ti-linux-kernel

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Commit 4f032ac4122a77dbabf7a24b2739b2790448180f

Authored by Jack Steiner
Committed by Linus Torvalds
1 parent 2d09cde985
Exists in master and in 20 other branches dlt-processor-sdk-linux-03.00.00.04, newt-ti-linux-3.12.y, processor-sdk-linux-01.00.00, processor-sdk-linux-02.00.01, smarc-ti-linux-3.12.10, smarc-ti-linux-3.12.y, smarc-ti-linux-3.14.y, smarc-ti-linux-3.15.y, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04, ti-linux-3.12.y, ti-linux-3.14.y, ti-linux-3.15.y, ti-lsk-linux-4.1.y

cpumask: fix slab corruption caused by alloc_cpumask_var_node() 

Fix slab corruption caused by alloc_cpumask_var_node() overwriting the
tail end of an off-stack cpumask.

The function zeros out cpumask bits beyond the last possible cpu.  The
starting point for zeroing should be the beginning of the mask offset by a
byte count derived from the number of possible cpus.  The offset was
calculated in bits instead of bytes.  This resulted in overwriting the end
of the cpumask.

Signed-off-by: Jack Steiner <steiner@sgi.com>
Acked-by: Mike Travis <travis.sgi.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: <stable@kernel.org>		[2.6.29.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 1 changed file with 2 additions and 2 deletions Side-by-side Diff

... ... @@ -109,10 +109,10 @@
109 109 #endif
110 110 /* FIXME: Bandaid to save us from old primitives which go to NR_CPUS. */
111 111 if (*mask) {
  112 + unsigned char *ptr = (unsigned char *)cpumask_bits(*mask);
112 113 unsigned int tail;
113 114 tail = BITS_TO_LONGS(NR_CPUS - nr_cpumask_bits) * sizeof(long);
114   - memset(cpumask_bits(*mask) + cpumask_size() - tail,
115   - 0, tail);
  115 + memset(ptr + cpumask_size() - tail, 0, tail);
116 116 }
117 117  
118 118 return *mask != NULL;