4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: He Zhe zhe.he@windriver.com
commit ccde460b9ae5c2bd5e4742af0a7f623c2daad566 upstream.
memory_corruption_check[{_period|_size}]()'s handlers do not check input argument before passing it to kstrtoul() or simple_strtoull(). The argument would be a NULL pointer if each of the kernel parameters, without its value, is set in command line and thus cause the following panic.
PANIC: early exception 0xe3 IP 10:ffffffff73587c22 error 0 cr2 0x0 [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.18-rc8+ #2 [ 0.000000] RIP: 0010:kstrtoull+0x2/0x10 ... [ 0.000000] Call Trace [ 0.000000] ? set_corruption_check+0x21/0x49 [ 0.000000] ? do_early_param+0x4d/0x82 [ 0.000000] ? parse_args+0x212/0x330 [ 0.000000] ? rdinit_setup+0x26/0x26 [ 0.000000] ? parse_early_options+0x20/0x23 [ 0.000000] ? rdinit_setup+0x26/0x26 [ 0.000000] ? parse_early_param+0x2d/0x39 [ 0.000000] ? setup_arch+0x2f7/0xbf4 [ 0.000000] ? start_kernel+0x5e/0x4c2 [ 0.000000] ? load_ucode_bsp+0x113/0x12f [ 0.000000] ? secondary_startup_64+0xa5/0xb0
This patch adds checks to prevent the panic.
Signed-off-by: He Zhe zhe.he@windriver.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Cc: gregkh@linuxfoundation.org Cc: kstewart@linuxfoundation.org Cc: pombredanne@nexb.com Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1534260823-87917-1-git-send-email-zhe.he@windriver.... Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/kernel/check.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)
--- a/arch/x86/kernel/check.c +++ b/arch/x86/kernel/check.c @@ -30,6 +30,11 @@ static __init int set_corruption_check(c ssize_t ret; unsigned long val;
+ if (!arg) { + pr_err("memory_corruption_check config string not provided\n"); + return -EINVAL; + } + ret = kstrtoul(arg, 10, &val); if (ret) return ret; @@ -44,6 +49,11 @@ static __init int set_corruption_check_p ssize_t ret; unsigned long val;
+ if (!arg) { + pr_err("memory_corruption_check_period config string not provided\n"); + return -EINVAL; + } + ret = kstrtoul(arg, 10, &val); if (ret) return ret; @@ -58,6 +68,11 @@ static __init int set_corruption_check_s char *end; unsigned size;
+ if (!arg) { + pr_err("memory_corruption_check_size config string not provided\n"); + return -EINVAL; + } + size = memparse(arg, &end);
if (*end == '\0')