9fad9d560a
Running syzkaller with the newly reintroduced signed integer overflow sanitizer produces this report: [ 65.194362] ------------[ cut here ]------------ [ 65.197752] UBSAN: signed-integer-overflow in ../drivers/scsi/sr_ioctl.c:436:9 [ 65.203607] -2147483648 * 177 cannot be represented in type 'int' [ 65.207911] CPU: 2 PID: 10416 Comm: syz-executor.1 Not tainted 6.8.0-rc2-00035-gb3ef86b5a957 #1 [ 65.213585] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 65.219923] Call Trace: [ 65.221556] <TASK> [ 65.223029] dump_stack_lvl+0x93/0xd0 [ 65.225573] handle_overflow+0x171/0x1b0 [ 65.228219] sr_select_speed+0xeb/0xf0 [ 65.230786] ? __pm_runtime_resume+0xe6/0x130 [ 65.233606] sr_block_ioctl+0x15d/0x1d0 ... Historically, the signed integer overflow sanitizer did not work in the kernel due to its interaction with `-fwrapv` but this has since been changed [1] in the newest version of Clang. It was re-enabled in the kernel with Commit 557f8c582a9b ("ubsan: Reintroduce signed overflow sanitizer"). Firstly, let's change the type of "speed" to unsigned long as sr_select_speed()'s only caller passes in an unsigned long anyways. $ git grep '\.select_speed' | drivers/scsi/sr.c: .select_speed = sr_select_speed, ... | static int cdrom_ioctl_select_speed(struct cdrom_device_info *cdi, | unsigned long arg) | { | ... | return cdi->ops->select_speed(cdi, arg); | } Next, let's add an extra check to make sure we don't exceed 0xffff/177 (350) since 0xffff is the max speed. This has two benefits: 1) we deal with integer overflow before it happens and 2) we properly respect the max speed of 0xffff. There are some "magic" numbers here but I did not want to change more than what was necessary. Link: https://github.com/llvm/llvm-project/pull/82432 [1] Closes: https://github.com/KSPP/linux/issues/357 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240508-b4-b4-sio-sr_select_speed-v2-1-00b68f724290@google.com Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> |
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| acpi | ||
| asm-generic | ||
| clocksource | ||
| crypto | ||
| drm | ||
| dt-bindings | ||
| keys | ||
| kunit | ||
| kvm | ||
| linux | ||
| math-emu | ||
| media | ||
| memory | ||
| misc | ||
| net | ||
| pcmcia | ||
| ras | ||
| rdma | ||
| rv | ||
| scsi | ||
| soc | ||
| sound | ||
| target | ||
| trace | ||
| uapi | ||
| ufs | ||
| vdso | ||
| video | ||
| xen | ||