3.7-stable review patch. If anyone has any objections, please let me know.
------------------ From: Maxime Bizon <[email protected]> commit b042e47491ba5f487601b5141a3f1d8582304170 upstream. record_size / console_size / ftrace_size can be 0 (this is how you disable the feature), but rounddown_pow_of_two(0) is undefined. As suggested by Kees Cook, use !is_power_of_2() as a condition to call rounddown_pow_of_two and avoid its undefined behavior on the value 0. This issue has been present since commit 1894a253 (ramoops: Move to fs/pstore/ram.c). Signed-off-by: Maxime Bizon <[email protected]> Signed-off-by: Florian Fainelli <[email protected]> Acked-by: Kees Cook <[email protected]> Signed-off-by: Anton Vorontsov <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/pstore/ram.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -374,10 +374,14 @@ static int __devinit ramoops_probe(struc goto fail_out; } - pdata->mem_size = rounddown_pow_of_two(pdata->mem_size); - pdata->record_size = rounddown_pow_of_two(pdata->record_size); - pdata->console_size = rounddown_pow_of_two(pdata->console_size); - pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size); + if (!is_power_of_2(pdata->mem_size)) + pdata->mem_size = rounddown_pow_of_two(pdata->mem_size); + if (!is_power_of_2(pdata->record_size)) + pdata->record_size = rounddown_pow_of_two(pdata->record_size); + if (!is_power_of_2(pdata->console_size)) + pdata->console_size = rounddown_pow_of_two(pdata->console_size); + if (!is_power_of_2(pdata->ftrace_size)) + pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size); cxt->dump_read_cnt = 0; cxt->size = pdata->mem_size; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
