The patch titled Subject: Revert "kernel/reboot.c: convert simple_strtoul to kstrtoint" has been added to the -mm tree. Its filename is revert-kernel-rebootc-convert-simple_strtoul-to-kstrtoint.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/revert-kernel-rebootc-convert-simple_strtoul-to-kstrtoint.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/revert-kernel-rebootc-convert-simple_strtoul-to-kstrtoint.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Matteo Croce <mcroce@xxxxxxxxxxxxx> Subject: Revert "kernel/reboot.c: convert simple_strtoul to kstrtoint" Patch series "fix parsing of reboot= cmdline", v3. The parsing of the reboot= cmdline has two major errors: - a missing bound check can crash the system on reboot - parsing of the cpu number only works if specified last Fix both. This patch (of 2): This reverts commit 616feab753972b97. kstrtoint() and simple_strtoul() have a subtle difference which makes them non interchangeable: if a non digit character is found amid the parsing, the former will return an error, while the latter will just stop parsing, e.g. simple_strtoul("123xyx") = 123. The kernel cmdline reboot= argument allows to specify the CPU used for rebooting, with the syntax `s####` among the other flags, e.g. "reboot=warm,s31,force", so if this flag is not the last given, it's silently ignored as well as the subsequent ones. Link: https://lkml.kernel.org/r/20201103214025.116799-2-mcroce@xxxxxxxxxxxxxxxxxxx Fixes: 616feab75397 ("kernel/reboot.c: convert simple_strtoul to kstrtoint") Signed-off-by: Matteo Croce <mcroce@xxxxxxxxxxxxx> Cc: Guenter Roeck <linux@xxxxxxxxxxxx> Cc: Petr Mladek <pmladek@xxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: Mike Rapoport <rppt@xxxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx> Cc: Robin Holt <robinmholt@xxxxxxxxx> Cc: Fabian Frederick <fabf@xxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/reboot.c | 21 +++++++-------------- 1 file changed, 7 insertions(+), 14 deletions(-) --- a/kernel/reboot.c~revert-kernel-rebootc-convert-simple_strtoul-to-kstrtoint +++ a/kernel/reboot.c @@ -551,22 +551,15 @@ static int __init reboot_setup(char *str break; case 's': - { - int rc; - - if (isdigit(*(str+1))) { - rc = kstrtoint(str+1, 0, &reboot_cpu); - if (rc) - return rc; - } else if (str[1] == 'm' && str[2] == 'p' && - isdigit(*(str+3))) { - rc = kstrtoint(str+3, 0, &reboot_cpu); - if (rc) - return rc; - } else + if (isdigit(*(str+1))) + reboot_cpu = simple_strtoul(str+1, NULL, 0); + else if (str[1] == 'm' && str[2] == 'p' && + isdigit(*(str+3))) + reboot_cpu = simple_strtoul(str+3, NULL, 0); + else *mode = REBOOT_SOFT; break; - } + case 'g': *mode = REBOOT_GPIO; break; _ Patches currently in -mm which might be from mcroce@xxxxxxxxxxxxx are revert-kernel-rebootc-convert-simple_strtoul-to-kstrtoint.patch reboot-fix-overflow-parsing-reboot-cpu-number.patch reboot-refactor-and-comment-the-cpu-selection-code.patch