diff options
| author | Naga Chumbalkar <nagananda.chumbalkar@hp.com> | 2011-09-14 16:22:23 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-10-03 11:40:31 -0700 |
| commit | c780713f786ee22532839502ed35f1bd1cb0fd1d (patch) | |
| tree | 20c95ac2bbcd673a0c878c725cacb9c52dbc11c5 /drivers/cpufreq | |
| parent | d9575b0bf2b1c380bde6803739513ccc1f95d1d0 (diff) | |
drivers/cpufreq/pcc-cpufreq.c: avoid NULL pointer dereference
commit e71f5cc402ecb42b407ae52add7b173bf1c53daa upstream.
per_cpu(processors, n) can be NULL, resulting in:
Loading CPUFreq modules[ 437.661360] BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffffa0434314>] pcc_cpufreq_cpu_init+0x74/0x220 [pcc_cpufreq]
It's better to avoid the oops by failing the driver, and allowing the
system to boot.
Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/cpufreq')
| -rw-r--r-- | drivers/cpufreq/pcc-cpufreq.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/cpufreq/pcc-cpufreq.c b/drivers/cpufreq/pcc-cpufreq.c index 7b0603eb0129..cdc02ac8f41a 100644 --- a/drivers/cpufreq/pcc-cpufreq.c +++ b/drivers/cpufreq/pcc-cpufreq.c @@ -261,6 +261,9 @@ static int pcc_get_offset(int cpu) pr = per_cpu(processors, cpu); pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu); + if (!pr) + return -ENODEV; + status = acpi_evaluate_object(pr->handle, "PCCP", NULL, &buffer); if (ACPI_FAILURE(status)) return -ENODEV; |