Petr Mladek eac48eb6ce printk: ringbuffer: Wrong data pointer when appending small string ... data_realloc() returns wrong data pointer when the block is wrapped and the size is not increased. It might happen when pr_cont() wants to add only few characters and there is already a space for them because of alignment. It might cause writing outsite the buffer. It has been detected by LTP tests with KASAN enabled: [ 221.921944] oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null),cpuset=c,mems_allowed=0,oom_memcg=/0,task_memcg=in [ 221.922108] ================================================================== [ 221.922111] BUG: KASAN: global-out-of-bounds in vprintk_store+0x362/0x3d0 [ 221.922112] Write of size 2 at addr ffffffffba51dbcd by task memcg_test_1/11282 [ 221.922113] [ 221.922114] CPU: 1 PID: 11282 Comm: memcg_test_1 Not tainted 5.9.0-next-20201013 #1 [ 221.922116] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS 2.0b 07/27/2017 [ 221.922116] Call Trace: [ 221.922117] dump_stack+0xa4/0xd9 [ 221.922118] print_address_description.constprop.0+0x21/0x210 [ 221.922119] ? _raw_write_lock_bh+0xe0/0xe0 [ 221.922120] ? vprintk_store+0x362/0x3d0 [ 221.922121] kasan_report.cold+0x37/0x7c [ 221.922122] ? vprintk_store+0x362/0x3d0 [ 221.922123] check_memory_region+0x18c/0x1f0 [ 221.922124] memcpy+0x3c/0x60 [ 221.922125] vprintk_store+0x362/0x3d0 [ 221.922125] ? __ia32_sys_syslog+0x50/0x50 [ 221.922126] ? _raw_spin_lock_irqsave+0x9b/0x100 [ 221.922127] ? _raw_spin_lock_irq+0xf0/0xf0 [ 221.922128] ? __kasan_check_write+0x14/0x20 [ 221.922129] vprintk_emit+0x8d/0x1f0 [ 221.922130] vprintk_default+0x1d/0x20 [ 221.922131] vprintk_func+0x5a/0x100 [ 221.922132] printk+0xb2/0xe3 [ 221.922133] ? swsusp_write.cold+0x189/0x189 [ 221.922134] ? kernfs_vfs_xattr_set+0x60/0x60 [ 221.922134] ? _raw_write_lock_bh+0xe0/0xe0 [ 221.922135] ? trace_hardirqs_on+0x38/0x100 [ 221.922136] pr_cont_kernfs_path.cold+0x49/0x4b [ 221.922137] mem_cgroup_print_oom_context.cold+0x74/0xc3 [ 221.922138] dump_header+0x340/0x3bf [ 221.922139] oom_kill_process.cold+0xb/0x10 [ 221.922140] out_of_memory+0x1e9/0x860 [ 221.922141] ? oom_killer_disable+0x210/0x210 [ 221.922142] mem_cgroup_out_of_memory+0x198/0x1c0 [ 221.922143] ? mem_cgroup_count_precharge_pte_range+0x250/0x250 [ 221.922144] try_charge+0xa9b/0xc50 [ 221.922145] ? arch_stack_walk+0x9e/0xf0 [ 221.922146] ? memory_high_write+0x230/0x230 [ 221.922146] ? avc_has_extended_perms+0x830/0x830 [ 221.922147] ? stack_trace_save+0x94/0xc0 [ 221.922148] ? stack_trace_consume_entry+0x90/0x90 [ 221.922149] __memcg_kmem_charge+0x73/0x120 [ 221.922150] ? cred_has_capability+0x10f/0x200 [ 221.922151] ? mem_cgroup_can_attach+0x260/0x260 [ 221.922152] ? selinux_sb_eat_lsm_opts+0x2f0/0x2f0 [ 221.922153] ? obj_cgroup_charge+0x16b/0x220 [ 221.922154] ? kmem_cache_alloc+0x78/0x4c0 [ 221.922155] obj_cgroup_charge+0x122/0x220 [ 221.922156] ? vm_area_alloc+0x20/0x90 [ 221.922156] kmem_cache_alloc+0x78/0x4c0 [ 221.922157] vm_area_alloc+0x20/0x90 [ 221.922158] mmap_region+0x3ed/0x9a0 [ 221.922159] ? cap_mmap_addr+0x1d/0x80 [ 221.922160] do_mmap+0x3ee/0x720 [ 221.922161] vm_mmap_pgoff+0x16a/0x1c0 [ 221.922162] ? randomize_stack_top+0x90/0x90 [ 221.922163] ? copy_page_range+0x1980/0x1980 [ 221.922163] ksys_mmap_pgoff+0xab/0x350 [ 221.922164] ? find_mergeable_anon_vma+0x110/0x110 [ 221.922165] ? __audit_syscall_entry+0x1a6/0x1e0 [ 221.922166] __x64_sys_mmap+0x8d/0xb0 [ 221.922167] do_syscall_64+0x38/0x50 [ 221.922168] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 221.922169] RIP: 0033:0x7fe8f5e75103 [ 221.922172] Code: 54 41 89 d4 55 48 89 fd 53 4c 89 cb 48 85 ff 74 56 49 89 d9 45 89 f8 45 89 f2 44 89 e2 4c 89 ee 48 89 ef b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 7d 5b 5d 41 5c 41 5d 41 5e 41 5f c3 66 2e 0f [ 221.922173] RSP: 002b:00007ffd38c90198 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 [ 221.922175] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe8f5e75103 [ 221.922176] RDX: 0000000000000003 RSI: 0000000000001000 RDI: 0000000000000000 [ 221.922178] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 221.922179] R10: 0000000000002022 R11: 0000000000000246 R12: 0000000000000003 [ 221.922180] R13: 0000000000001000 R14: 0000000000002022 R15: 0000000000000000 [ 221.922181] [ 213O[ 221.922182] The buggy address belongs to the variable: [ 221.922183] clear_seq+0x2d/0x40 [ 221.922183] [ 221.922184] Memory state around the buggy address: [ 221.922185] ffffffffba51da80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 221.922187] ffffffffba51db00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 221.922188] >ffffffffba51db80: f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9 [ 221.922189] ^ [ 221.922190] ffffffffba51dc00: f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9 [ 221.922191] ffffffffba51dc80: f9 f9 f9 f9 01 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9 [ 221.922193] ================================================================== [ 221.922194] Disabling lock debugging due to kernel taint [ 221.922196] ,task=memcg_test_1,pid=11280,uid=0 [ 221.922205] Memory cgroup out of memory: Killed process 11280 Link: https://lore.kernel.org/r/CA+G9fYt46oC7-BKryNDaaXPJ9GztvS2cs_7GjYRjanRi4+ryCQ@mail.gmail.com Fixes: 4cfc7258f8 ("printk: ringbuffer: add finalization/extension support") Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Reviewed-by: John Ogness <john.ogness@linutronix.de> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20201014175051.GC13775@alley		2020-10-15 12:21:13 +02:00
..
bpf	bpf: Fix scalar32_min_max_or bounds tracking	2020-10-08 11:02:53 +02:00
cgroup	for-5.9/block-20200802	2020-08-03 11:57:03 -07:00
configs	compiler: remove CONFIG_OPTIMIZE_INLINING entirely	2020-04-07 10:43:42 -07:00
debug	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
dma	dma-pool: Fix an uninitialized variable bug in atomic_pool_expand()	2020-08-27 09:22:56 +02:00
entry	* Misc minor cleanups.	2020-10-12 10:51:02 -07:00
events	These are the performance events changes for v5.10:	2020-10-12 14:14:35 -07:00
gcov	gcov: add support for GCC 10.1	2020-09-11 09:33:54 -07:00
irq	Surgery of the MSI interrupt handling to prepare the support of upcoming	2020-10-12 11:40:41 -07:00
kcsan	kcsan: Use tracing-safe version of prandom	2020-08-30 21:50:13 -07:00
livepatch	livepatch: Make klp_apply_object_relocs static	2020-05-11 00:31:38 +02:00
locking	Merge branch 'locking/urgent' into locking/core, to pick up fixes	2020-10-09 08:55:17 +02:00
power	block-5.10-2020-10-12	2020-10-13 12:12:44 -07:00
printk	printk: ringbuffer: Wrong data pointer when appending small string	2020-10-15 12:21:13 +02:00
rcu	A small set of updates for debug objects:	2020-10-12 11:21:24 -07:00
sched	Scheduler changes for v5.10:	2020-10-12 12:56:01 -07:00
time	These are the locking updates for v5.10:	2020-10-12 13:06:20 -07:00
trace	block-5.10-2020-10-12	2020-10-13 12:12:44 -07:00
.gitignore
acct.c	mmap locking API: convert mmap_sem comments	2020-06-09 09:39:14 -07:00
async.c	treewide: Remove uninitialized_var() usage	2020-07-16 12:35:15 -07:00
audit_fsnotify.c	fsnotify: create method handle_inode_event() in fsnotify_operations	2020-07-27 23:25:50 +02:00
audit_tree.c	\n	2020-08-06 19:29:51 -07:00
audit_watch.c	fsnotify: create method handle_inode_event() in fsnotify_operations	2020-07-27 23:25:50 +02:00
audit.c	audit/stable-5.9 PR 20200803	2020-08-04 14:20:26 -07:00
audit.h	revert: 1320a4052e ("audit: trigger accompanying records when no rules present")	2020-07-29 10:00:36 -04:00
auditfilter.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
auditsc.c	audit/stable-5.9 PR 20200803	2020-08-04 14:20:26 -07:00
backtracetest.c	treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD()	2020-07-30 11:15:58 -07:00
bounds.c
capability.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
compat.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
configs.c
context_tracking.c	context_tracking: Ensure that the critical path cannot be instrumented	2020-06-11 15:14:36 +02:00
cpu_pm.c	notifier: Fix broken error handling pattern	2020-09-01 09:58:03 +02:00
cpu.c	The changes in this cycle are:	2020-06-03 13:06:42 -07:00
crash_core.c	kdump: append kernel build-id string to VMCOREINFO	2020-08-12 10:58:01 -07:00
crash_dump.c	crash_dump: Remove no longer used saved_max_pfn	2020-04-15 11:21:54 +02:00
cred.c	exec: Teach prepare_exec_creds how exec treats uids & gids	2020-05-20 14:44:21 -05:00
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c	kernel: add a kernel_wait helper	2020-08-12 10:57:59 -07:00
extable.c	kernel/extable.c: use address-of operator on section symbols	2020-04-07 10:43:42 -07:00
fail_function.c
fork.c	io_uring: don't rely on weak ->files references	2020-09-30 20:32:32 -06:00
freezer.c
futex.c	futex: Convert to use the preferred 'fallthrough' macro	2020-08-13 21:02:12 +02:00
gen_kheaders.sh	kbuild: add variables for compression tools	2020-06-06 23:42:01 +09:00
groups.c	mm: remove the pgprot argument to __vmalloc	2020-06-02 10:59:11 -07:00
hung_task.c	kernel/hung_task.c: introduce sysctl to print all traces when a hung task is detected	2020-06-08 11:05:56 -07:00
iomem.c
irq_work.c	irq_work, smp: Allow irq_work on call_single_queue	2020-05-28 10:54:15 +02:00
jump_label.c	jump_label,module: Fix module lifetime for __jump_label_mod_text_reserved()	2020-09-01 09:58:04 +02:00
kallsyms.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c	kcov: make some symbols static	2020-08-12 10:58:02 -07:00
kexec_core.c
kexec_elf.c
kexec_file.c	Misc fixes and small updates all around the place:	2020-08-15 10:38:03 -07:00
kexec_internal.h
kexec.c
kheaders.c
kmod.c	kmod: remove redundant "be an" in the comment	2020-08-12 10:58:01 -07:00
kprobes.c	This tree prepares to unify the kretprobe trampoline handler and make	2020-10-12 14:21:15 -07:00
ksysfs.c
kthread.c	uaccess: add force_uaccess_{begin,end} helpers	2020-08-12 10:57:59 -07:00
latencytop.c	sysctl: pass kernel pointers to ->proc_handler	2020-04-27 02:07:40 -04:00
Makefile	static_call: Add inline static call infrastructure	2020-09-01 09:58:04 +02:00
module_signature.c
module_signing.c
module-internal.h
module.c	static_call: Add inline static call infrastructure	2020-09-01 09:58:04 +02:00
notifier.c	notifier: Fix broken error handling pattern	2020-09-01 09:58:03 +02:00
nsproxy.c	nsproxy: support CLONE_NEWTIME with setns()	2020-07-08 11:14:22 +02:00
padata.c	padata: fix possible padata_works_lock deadlock	2020-09-04 17:51:55 +10:00
panic.c	panic: make print_oops_end_marker() static	2020-08-12 10:58:02 -07:00
params.c
pid_namespace.c	pid_namespace: use checkpoint_restore_ns_capable() for ns_last_pid	2020-07-19 20:14:42 +02:00
pid.c	cap-checkpoint-restore-v5.9	2020-08-04 15:02:07 -07:00
profile.c
ptrace.c
range.c
reboot.c	arch: remove unicore32 port	2020-07-01 12:09:13 +03:00
regset.c	regset: kill ->get()	2020-07-27 14:31:12 -04:00
relay.c	kernel/relay.c: fix memleak on destroy relay channel	2020-08-21 09:52:53 -07:00
resource.c	/dev/mem: Revoke mappings when a driver claims the region	2020-05-27 11:10:05 +02:00
rseq.c
scs.c	mm: memcontrol: account kernel stack per node	2020-08-07 11:33:25 -07:00
seccomp.c	seccomp: don't leave dangling ->notif if file allocation fails	2020-09-08 11:30:16 -07:00
signal.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
smp.c	smp: Fix a potential usage of stale nr_cpus	2020-07-22 10:22:04 +02:00
smpboot.c
smpboot.h
softirq.c	softirq: Add debug check to __raise_softirq_irqoff()	2020-09-16 15:18:56 +02:00
stackleak.c	stackleak: let stack_erasing_sysctl take a kernel pointer buffer	2020-09-19 13:13:39 -07:00
stacktrace.c	stacktrace: Remove reliable argument from arch_stack_walk() callback	2020-09-18 14:24:16 +01:00
static_call.c	static_call: Fix return type of static_call_init	2020-10-02 21:18:25 +02:00
stop_machine.c
sys_ni.c	quota: simplify the quotactl compat handling	2020-09-17 13:00:46 -04:00
sys.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
sysctl-test.c
sysctl.c	mm: allow a controlled amount of unfairness in the page lock	2020-09-17 10:26:41 -07:00
task_work.c	task_work: only grab task signal lock when needed	2020-08-13 09:01:38 -06:00
taskstats.c
test_kprobes.c
torture.c	torture: Dump ftrace at shutdown only if requested	2020-06-29 12:01:45 -07:00
tracepoint.c	tracepoint: Fix out of sync data passing by static caller	2020-10-02 21:18:25 +02:00
tsacct.c
ucount.c	ucount: Make sure ucounts in /proc/sys/user don't regress again	2020-04-07 21:51:27 +02:00
uid16.c
uid16.h
umh.c	usermodehelper: reset umask to default before executing user process	2020-10-06 10:31:52 -07:00
up.c
user_namespace.c	nsproxy: add struct nsset	2020-05-09 13:57:12 +02:00
user-return-notifier.c
user.c	user.c: make uidhash_table static	2020-06-04 19:06:24 -07:00
usermode_driver.c	umd: Stop using split_argv	2020-07-07 11:58:59 -05:00
utsname_sysctl.c	sysctl: pass kernel pointers to ->proc_handler	2020-04-27 02:07:40 -04:00
utsname.c	nsproxy: add struct nsset	2020-05-09 13:57:12 +02:00
watch_queue.c	watch_queue: Limit the number of watches a user can hold	2020-08-17 09:39:18 -07:00
watchdog_hld.c
watchdog.c	kernel/watchdog.c: convert {soft/hard}lockup boot parameters to sysctl aliases	2020-06-08 11:05:56 -07:00
workqueue_internal.h
workqueue.c	treewide: Make all debug_obj_descriptors const	2020-09-24 21:56:25 +02:00