Chen Zhongjin f0c151602f profiling: fix shift too large makes kernel panic ... [ Upstream commit 0fe6ee8f12 ] 2d186afd04 ("profiling: fix shift-out-of-bounds bugs") limits shift value by [0, BITS_PER_LONG -1], which means [0, 63]. However, syzbot found that the max shift value should be the bit number of (_etext - _stext). If shift is outside of this, the "buffer_bytes" will be zero and will cause kzalloc(0). Then the kernel panics due to dereferencing the returned pointer 16. This can be easily reproduced by passing a large number like 60 to enable profiling and then run readprofile. LOGS: BUG: kernel NULL pointer dereference, address: 0000000000000010 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 6148067 P4D 6148067 PUD 6142067 PMD 0 PREEMPT SMP CPU: 4 PID: 184 Comm: readprofile Not tainted 5.18.0+ #162 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 RIP: 0010:read_profile+0x104/0x220 RSP: 0018:ffffc900006fbe80 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff888006150000 RSI: 0000000000000001 RDI: ffffffff82aba4a0 RBP: 000000000188bb60 R08: 0000000000000010 R09: ffff888006151000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82aba4a0 R13: 0000000000000000 R14: ffffc900006fbf08 R15: 0000000000020c30 FS: 000000000188a8c0(0000) GS:ffff88803ed00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 0000000006144000 CR4: 00000000000006e0 Call Trace: <TASK> proc_reg_read+0x56/0x70 vfs_read+0x9a/0x1b0 ksys_read+0xa1/0xe0 ? fpregs_assert_state_consistent+0x1e/0x40 do_syscall_64+0x3a/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x4d4b4e RSP: 002b:00007ffebb668d58 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000000000188a8a0 RCX: 00000000004d4b4e RDX: 0000000000000400 RSI: 000000000188bb60 RDI: 0000000000000003 RBP: 0000000000000003 R08: 000000000000006e R09: 0000000000000000 R10: 0000000000000041 R11: 0000000000000246 R12: 000000000188bb60 R13: 0000000000000400 R14: 0000000000000000 R15: 000000000188bb60 </TASK> Modules linked in: CR2: 0000000000000010 Killed ---[ end trace 0000000000000000 ]--- Check prof_len in profile_init() to prevent it be zero. Link: https://lkml.kernel.org/r/20220531012854.229439-1-chenzhongjin@huawei.com Fixes: 1da177e4c3 ("Linux-2.6.12-rc2") Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>		2022-08-17 14:24:04 +02:00
..
bpf	bpf: Fix subprog names in stack traces.	2022-08-17 14:23:30 +02:00
cgroup	cgroup: Use separate src/dst nodes when preloading css_sets for migration	2022-07-21 21:24:13 +02:00
configs
debug
dma	dma-direct: use the correct size for dma_set_encrypted()	2022-06-29 09:03:31 +02:00
entry
events	perf/core: Fix data race between perf_event_set_output() and perf_mmap_close()	2022-07-29 17:25:11 +02:00
gcov
irq	irqdomain: Report irq number for NOMAP domains	2022-08-17 14:23:14 +02:00
kcsan
livepatch
locking	locking/lockdep: Fix lockdep_init_map_*() confusion	2022-08-17 14:23:08 +02:00
power	PM: hibernate: defer device probing when resuming from hibernation	2022-08-17 14:23:04 +02:00
printk
rcu	rcutorture: Fix ksoftirqd boosting timing and iteration	2022-08-17 14:23:23 +02:00
sched	nohz/full, sched/rt: Fix missed tick-reenabling bug in dequeue_task_rt()	2022-08-17 14:23:14 +02:00
time	wireguard: ratelimiter: use hrtimer in selftest	2022-08-17 14:23:37 +02:00
trace	blktrace: Trace remapped requests correctly	2022-08-17 14:23:13 +02:00
.gitignore
acct.c
async.c
audit.c
audit.h
audit_fsnotify.c
audit_tree.c
audit_watch.c
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c
cfi.c	cfi: Fix __cfi_slowpath_diag RCU usage with cpuidle	2022-06-22 14:22:04 +02:00
compat.c
configs.c
context_tracking.c
cpu.c
cpu_pm.c
crash_core.c
crash_dump.c
cred.c
delayacct.c
dma.c
exec_domain.c
exit.c	fix race between exit_itimers() and /proc/pid/timers	2022-07-21 21:24:11 +02:00
extable.c
fail_function.c
fork.c
freezer.c
futex.c
gen_kheaders.sh
groups.c
hung_task.c
iomem.c
irq_work.c
jump_label.c
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c
kexec.c
kexec_core.c
kexec_elf.c
kexec_file.c	ima: force signature verification when CONFIG_KEXEC_SIG is configured	2022-07-21 21:24:29 +02:00
kexec_internal.h
kheaders.c
kmod.c
kprobes.c
ksysfs.c
kthread.c
latencytop.c
Makefile
module-internal.h
module.c	module: fix [e_shstrndx].sh_size=0 OOB access	2022-07-12 16:35:09 +02:00
module_signature.c
module_signing.c
notifier.c
nsproxy.c
padata.c
panic.c
params.c
pid.c
pid_namespace.c
profile.c	profiling: fix shift too large makes kernel panic	2022-08-17 14:24:04 +02:00
ptrace.c
range.c
reboot.c
regset.c
relay.c
resource.c
resource_kunit.c
rseq.c
scftorture.c
scs.c
seccomp.c
signal.c	signal handling: don't use BUG_ON() for debugging	2022-07-21 21:24:42 +02:00
smp.c
smpboot.c
smpboot.h
softirq.c
stackleak.c
stacktrace.c
static_call.c
static_call_inline.c
stop_machine.c
sys.c
sys_ni.c
sysctl-test.c
sysctl.c	sysctl: move some boundary constants from sysctl.c to sysctl_vals	2022-07-29 17:25:11 +02:00
task_work.c
taskstats.c
test_kprobes.c
torture.c
tracepoint.c
tsacct.c
ucount.c
uid16.c
uid16.h
umh.c
up.c
user-return-notifier.c
user.c
user_namespace.c
usermode_driver.c
utsname.c
utsname_sysctl.c
watch_queue.c	watch_queue: Fix missing locking in add_watch_to_object()	2022-08-03 12:03:43 +02:00
watchdog.c
watchdog_hld.c
workqueue.c
workqueue_internal.h