| Message ID | 20201016180907.171957-2-mcroce@linux.microsoft.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] reboot: fix overflow parsing reboot cpu number | expand |
On Fri, Oct 16, 2020 at 08:09:06PM +0200, Matteo Croce wrote: > From: Matteo Croce <mcroce@microsoft.com> > > Limit the CPU number to num_possible_cpus(), because setting it > to a value lower than INT_MAX but higher than NR_CPUS produces the > following error on reboot and shutdown: > > BUG: unable to handle page fault for address: ffffffff90ab1bb0 > #PF: supervisor read access in kernel mode > #PF: error_code(0x0000) - not-present page > PGD 1c09067 P4D 1c09067 PUD 1c0a063 PMD 0 > Oops: 0000 [#1] SMP > CPU: 1 PID: 1 Comm: systemd-shutdow Not tainted 5.9.0-rc8-kvm #110 > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 > RIP: 0010:migrate_to_reboot_cpu+0xe/0x60 > Code: ea ea 00 48 89 fa 48 c7 c7 30 57 f1 81 e9 fa ef ff ff 66 2e 0f 1f 84 00 00 00 00 00 53 8b 1d d5 ea ea 00 e8 14 33 fe ff 89 da <48> 0f a3 15 ea fc bd 00 48 89 d0 73 29 89 c2 c1 e8 06 65 48 8b 3c > RSP: 0018:ffffc90000013e08 EFLAGS: 00010246 > RAX: ffff88801f0a0000 RBX: 0000000077359400 RCX: 0000000000000000 > RDX: 0000000077359400 RSI: 0000000000000002 RDI: ffffffff81c199e0 > RBP: ffffffff81c1e3c0 R08: ffff88801f41f000 R09: ffffffff81c1e348 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: 00007f32bedf8830 R14: 00000000fee1dead R15: 0000000000000000 > FS: 00007f32bedf8980(0000) GS:ffff88801f480000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffffff90ab1bb0 CR3: 000000001d057000 CR4: 00000000000006a0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > __do_sys_reboot.cold+0x34/0x5b > ? vfs_writev+0x92/0xc0 > ? do_writev+0x52/0xd0 > do_syscall_64+0x2d/0x40 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > RIP: 0033:0x7f32bfaaecd3 > Code: 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 89 fa be 69 19 12 28 bf ad de e1 fe b8 a9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 89 81 0c 00 f7 d8 > RSP: 002b:00007fff6265fb58 EFLAGS: 00000202 ORIG_RAX: 00000000000000a9 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f32bfaaecd3 > RDX: 0000000001234567 RSI: 0000000028121969 RDI: 00000000fee1dead > RBP: 0000000000000000 R08: 0000000000008020 R09: 00007fff6265ef60 > R10: 00007f32bedf8830 R11: 0000000000000202 R12: 0000000000000000 > R13: 0000557bba2c51c0 R14: 0000000000000000 R15: 00007fff6265fbc8 > CR2: ffffffff90ab1bb0 > ---[ end trace b813e80157136563 ]--- > RIP: 0010:migrate_to_reboot_cpu+0xe/0x60 > Code: ea ea 00 48 89 fa 48 c7 c7 30 57 f1 81 e9 fa ef ff ff 66 2e 0f 1f 84 00 00 00 00 00 53 8b 1d d5 ea ea 00 e8 14 33 fe ff 89 da <48> 0f a3 15 ea fc bd 00 48 89 d0 73 29 89 c2 c1 e8 06 65 48 8b 3c > RSP: 0018:ffffc90000013e08 EFLAGS: 00010246 > RAX: ffff88801f0a0000 RBX: 0000000077359400 RCX: 0000000000000000 > RDX: 0000000077359400 RSI: 0000000000000002 RDI: ffffffff81c199e0 > RBP: ffffffff81c1e3c0 R08: ffff88801f41f000 R09: ffffffff81c1e348 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: 00007f32bedf8830 R14: 00000000fee1dead R15: 0000000000000000 > FS: 00007f32bedf8980(0000) GS:ffff88801f480000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffffff90ab1bb0 CR3: 000000001d057000 CR4: 00000000000006a0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 > Kernel Offset: disabled > ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 ]--- > > Fixes: 1b3a5d02ee07 ("reboot: move arch/x86 reboot= handling to generic kernel") > Signed-off-by: Matteo Croce <mcroce@microsoft.com> Reviewed-by: Kees Cook <keescook@chromium.org> -- Kees Cook
On Fri, Oct 16, 2020 at 2:09 PM Matteo Croce <mcroce@linux.microsoft.com> wrote: > > From: Matteo Croce <mcroce@microsoft.com> > > Limit the CPU number to num_possible_cpus(), because setting it > to a value lower than INT_MAX but higher than NR_CPUS produces the > following error on reboot and shutdown: > > BUG: unable to handle page fault for address: ffffffff90ab1bb0 > #PF: supervisor read access in kernel mode > #PF: error_code(0x0000) - not-present page > PGD 1c09067 P4D 1c09067 PUD 1c0a063 PMD 0 > Oops: 0000 [#1] SMP > CPU: 1 PID: 1 Comm: systemd-shutdow Not tainted 5.9.0-rc8-kvm #110 > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 > RIP: 0010:migrate_to_reboot_cpu+0xe/0x60 > Code: ea ea 00 48 89 fa 48 c7 c7 30 57 f1 81 e9 fa ef ff ff 66 2e 0f 1f 84 00 00 00 00 00 53 8b 1d d5 ea ea 00 e8 14 33 fe ff 89 da <48> 0f a3 15 ea fc bd 00 48 89 d0 73 29 89 c2 c1 e8 06 65 48 8b 3c > RSP: 0018:ffffc90000013e08 EFLAGS: 00010246 > RAX: ffff88801f0a0000 RBX: 0000000077359400 RCX: 0000000000000000 > RDX: 0000000077359400 RSI: 0000000000000002 RDI: ffffffff81c199e0 > RBP: ffffffff81c1e3c0 R08: ffff88801f41f000 R09: ffffffff81c1e348 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: 00007f32bedf8830 R14: 00000000fee1dead R15: 0000000000000000 > FS: 00007f32bedf8980(0000) GS:ffff88801f480000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffffff90ab1bb0 CR3: 000000001d057000 CR4: 00000000000006a0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > __do_sys_reboot.cold+0x34/0x5b > ? vfs_writev+0x92/0xc0 > ? do_writev+0x52/0xd0 > do_syscall_64+0x2d/0x40 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > RIP: 0033:0x7f32bfaaecd3 > Code: 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 89 fa be 69 19 12 28 bf ad de e1 fe b8 a9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 89 81 0c 00 f7 d8 > RSP: 002b:00007fff6265fb58 EFLAGS: 00000202 ORIG_RAX: 00000000000000a9 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f32bfaaecd3 > RDX: 0000000001234567 RSI: 0000000028121969 RDI: 00000000fee1dead > RBP: 0000000000000000 R08: 0000000000008020 R09: 00007fff6265ef60 > R10: 00007f32bedf8830 R11: 0000000000000202 R12: 0000000000000000 > R13: 0000557bba2c51c0 R14: 0000000000000000 R15: 00007fff6265fbc8 > CR2: ffffffff90ab1bb0 > ---[ end trace b813e80157136563 ]--- > RIP: 0010:migrate_to_reboot_cpu+0xe/0x60 > Code: ea ea 00 48 89 fa 48 c7 c7 30 57 f1 81 e9 fa ef ff ff 66 2e 0f 1f 84 00 00 00 00 00 53 8b 1d d5 ea ea 00 e8 14 33 fe ff 89 da <48> 0f a3 15 ea fc bd 00 48 89 d0 73 29 89 c2 c1 e8 06 65 48 8b 3c > RSP: 0018:ffffc90000013e08 EFLAGS: 00010246 > RAX: ffff88801f0a0000 RBX: 0000000077359400 RCX: 0000000000000000 > RDX: 0000000077359400 RSI: 0000000000000002 RDI: ffffffff81c199e0 > RBP: ffffffff81c1e3c0 R08: ffff88801f41f000 R09: ffffffff81c1e348 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: 00007f32bedf8830 R14: 00000000fee1dead R15: 0000000000000000 > FS: 00007f32bedf8980(0000) GS:ffff88801f480000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffffff90ab1bb0 CR3: 000000001d057000 CR4: 00000000000006a0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 > Kernel Offset: disabled > ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 ]--- > > Fixes: 1b3a5d02ee07 ("reboot: move arch/x86 reboot= handling to generic kernel") > Signed-off-by: Matteo Croce <mcroce@microsoft.com> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
On Fri 2020-10-16 20:09:06, Matteo Croce wrote: > From: Matteo Croce <mcroce@microsoft.com> > > Limit the CPU number to num_possible_cpus(), because setting it > to a value lower than INT_MAX but higher than NR_CPUS produces the > following error on reboot and shutdown: > > Fixes: 1b3a5d02ee07 ("reboot: move arch/x86 reboot= handling to generic kernel") > Signed-off-by: Matteo Croce <mcroce@microsoft.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Best Regards, Petr
diff --git a/kernel/reboot.c b/kernel/reboot.c index e7b78d5ae1ab..c4e7965c39b9 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -558,11 +558,19 @@ static int __init reboot_setup(char *str) rc = kstrtoint(str+1, 0, &reboot_cpu); if (rc) return rc; + if (reboot_cpu >= num_possible_cpus()) { + reboot_cpu = 0; + return -ERANGE; + } } else if (str[1] == 'm' && str[2] == 'p' && isdigit(*(str+3))) { rc = kstrtoint(str+3, 0, &reboot_cpu); if (rc) return rc; + if (reboot_cpu >= num_possible_cpus()) { + reboot_cpu = 0; + return -ERANGE; + } } else *mode = REBOOT_SOFT; break;