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Patrick Palka 000a7d66ec kernel/printk/printk.c: fix faulty logic in the case of recursive printk 
We shouldn't set text_len in the code path that detects printk recursion
because text_len corresponds to the length of the string inside textbuf.
A few lines down from the line

    text_len = strlen(recursion_msg);

is the line

    text_len += vscnprintf(text + text_len, ...);

So if printk detects recursion, it sets text_len to 29 (the length of
recursion_msg) and logs an error.  Then the message supplied by the
caller of printk is stored inside textbuf but offset by 29 bytes.  This
means that the output of the recursive call to printk will contain 29
bytes of garbage in front of it.

This defect is caused by commit 458df9fd48 ("printk: remove separate
printk_sched buffers and use printk buf instead") which turned the line

    text_len = vscnprintf(text, ...);

into

    text_len += vscnprintf(text + text_len, ...);

To fix this, this patch avoids setting text_len when logging the printk
recursion error.  This patch also marks unlikely() the branch leading up
to this code.

Fixes: 458df9fd48 ("printk: remove separate printk_sched buffers and use printk buf instead")
Signed-off-by: Patrick Palka <patrick@parcs.ath.cx>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 		2014-09-10 15:42:12 -07:00
..
bpf net: filter: split 'struct sk_filter' into socket and bpf parts 2014-08-02 15:03:58 -07:00
debug kdb: Use ktime_get_ts() 2014-06-12 16:18:45 +02:00
events Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-08-24 16:16:55 -07:00
gcov kernel/gcov/fs.c: remove unnecessary null test before debugfs_remove 2014-08-08 15:57:24 -07:00
irq irq: Export handle_fasteoi_irq 2014-08-25 21:13:30 +02:00
locking arch, locking: Ciao arch_mutex_cpu_relax() 2014-07-17 12:32:47 +02:00
power PM / sleep: Fix test_suspend= command line option 2014-09-03 01:21:03 +02:00
printk kernel/printk/printk.c: fix faulty logic in the case of recursive printk 2014-09-10 15:42:12 -07:00
rcu rcu: Make nocb leader kthreads process pending callbacks after spawning 2014-08-28 05:59:59 -07:00
sched Merge branches 'pm-sleep', 'pm-cpufreq' and 'pm-cpuidle' 2014-08-11 23:19:48 +02:00
time timekeeping: Update timekeeper before updating vsyscall and pvclock 2014-09-06 12:58:18 +02:00
trace trace: Fix epoll hang when we race with new entries 2014-08-25 20:18:11 -04:00
.gitignore
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Kconfig.freezer
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Kconfig.hz
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Kconfig.locks locking/rwsem: Add CONFIG_RWSEM_SPIN_ON_OWNER 2014-07-16 14:57:13 +02:00
Kconfig.preempt
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Makefile bin2c: move bin2c in scripts/basic 2014-08-08 15:57:32 -07:00
acct.c kernel/acct.c: fix coding style warnings and errors 2014-08-08 15:57:27 -07:00
async.c
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audit.c CAPABILITIES: remove undefined caps from all processes 2014-07-24 21:53:47 +10:00
audit.h
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audit_tree.c
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audit_watch.c
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auditfilter.c kernel/auditfilter.c: replace count*size kmalloc by kcalloc 2014-08-06 18:01:12 -07:00
auditsc.c auditsc: audit_krule mask accesses need bounds checking 2014-06-10 08:44:40 -07:00
backtracetest.c kernel/backtracetest.c: replace no level printk by pr_info() 2014-06-04 16:54:14 -07:00
bounds.c page-cgroup: get rid of NR_PCG_FLAGS 2014-08-08 15:57:18 -07:00
capability.c CAPABILITIES: remove undefined caps from all processes 2014-07-24 21:53:47 +10:00
cgroup.c cgroup: check cgroup liveliness before unbreaking kernfs 2014-09-05 01:36:19 +09:00
cgroup_freezer.c cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes 2014-07-15 11:05:09 -04:00
compat.c compat: nanosleep: Clarify error handling 2014-09-06 12:58:18 +02:00
configs.c
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context_tracking.c x86/kprobes: Fix build errors and blacklist context_track_user 2014-06-14 09:07:44 +02:00
cpu.c sched: Rework check_for_tasks() 2014-07-05 11:17:45 +02:00
cpu_pm.c
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cpuset.c Merge branch 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2014-08-04 10:11:28 -07:00
crash_dump.c
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cred.c
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delayacct.c delayacct: Remove braindamaged type conversions 2014-07-23 10:18:06 -07:00
dma.c
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elfcore.c
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exec_domain.c kernel/exec_domain.c: code clean-up 2014-06-04 16:54:15 -07:00
exit.c kernel/exit.c: fix coding style warnings and errors 2014-08-08 15:57:22 -07:00
extable.c
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fork.c seccomp: Replace BUG(!spin_is_locked()) with assert_spin_lock 2014-08-11 13:29:12 -07:00
freezer.c
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futex.c futex: Simplify futex_lock_pi_atomic() and make it more robust 2014-06-21 22:26:24 +02:00
futex_compat.c
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groups.c
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hung_task.c kernel/hung_task.c: convert simple_strtoul to kstrtouint 2014-06-04 16:54:15 -07:00
irq_work.c irq_work: Remove BUG_ON in irq_work_run() 2014-07-05 11:17:26 +02:00
jump_label.c
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kallsyms.c kernel/kallsyms.c: fix %pB when there's no symbol at the address 2014-08-08 15:57:18 -07:00
kcmp.c
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kexec.c kexec: create a new config option CONFIG_KEXEC_FILE for new syscall 2014-08-29 16:28:16 -07:00
kmod.c signals: change wait_for_helper() to use kernel_sigaction() 2014-06-06 16:08:12 -07:00
kprobes.c kprobes: Skip kretprobe hit in NMI context to avoid deadlock 2014-08-08 10:38:04 +02:00
ksysfs.c
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kthread.c kthread_work: wake up worker only when the worker is idle 2014-07-28 14:07:52 -04:00
latencytop.c kernel/latencytop.c: convert seq_printf to seq_puts 2014-06-04 16:54:15 -07:00
module-internal.h
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module.c module: Clean up ro/nx after early module load failures 2014-08-16 04:47:00 +09:30
module_signing.c
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notifier.c
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nsproxy.c namespaces: Use task_lock and not rcu to protect nsproxy 2014-07-29 18:08:50 -07:00
padata.c
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panic.c panic: add TAINT_SOFTLOCKUP 2014-08-08 15:57:24 -07:00
params.c Add module param type 'ullong' 2014-07-17 22:07:37 +02:00
pid.c
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pid_namespace.c
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profile.c kernel/profile.c: use static const char instead of static char 2014-06-06 16:08:13 -07:00
ptrace.c sched: Remove proliferation of wait_on_bit() action functions 2014-07-16 15:10:39 +02:00
range.c
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reboot.c kernel/reboot.c: convert simple_strtoul to kstrtoint 2014-06-04 16:54:15 -07:00
relay.c
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res_counter.c kernel/res_counter.c: replace simple_strtoull by kstrtoull 2014-06-04 16:54:15 -07:00
resource.c resource: fix the case of null pointer access 2014-08-29 16:28:15 -07:00
seccomp.c seccomp: Replace BUG(!spin_is_locked()) with assert_spin_lock 2014-08-11 13:29:12 -07:00
signal.c Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
smp.c kernel/smp.c:on_each_cpu_cond(): fix warning in fallback path 2014-08-06 18:01:22 -07:00
smpboot.c
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smpboot.h
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softirq.c
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stacktrace.c
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stop_machine.c kernel/stop_machine.c: kernel-doc warning fix 2014-06-04 16:54:15 -07:00
sys.c sched: move no_new_privs into new atomic flags 2014-07-18 12:13:38 -07:00
sys_ni.c kexec: new syscall kexec_file_load() declaration 2014-08-08 15:57:32 -07:00
sysctl.c mm, hugetlb: remove hugetlb_zero and hugetlb_infinity 2014-08-06 18:01:19 -07:00
sysctl_binary.c ipv6: Allow accepting RA from local IP addresses. 2014-07-01 12:16:24 -07:00
system_certificates.S
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system_keyring.c KEYS: validate certificate trust only with builtin keys 2014-07-17 09:35:17 -04:00
task_work.c
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taskstats.c
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test_kprobes.c kernel/test_kprobes.c: use current logging functions 2014-08-08 15:57:18 -07:00
torture.c torture: Avoid format string leak to thead name 2014-07-07 10:12:56 -07:00
tracepoint.c tracing: syscall_regfunc() should not skip kernel threads 2014-06-21 00:15:26 -04:00
tsacct.c sched: Make task->start_time nanoseconds based 2014-07-23 10:18:05 -07:00
uid16.c
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up.c
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user-return-notifier.c
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user.c kernel/user.c: drop unused field 'files' from user_struct 2014-06-04 16:54:16 -07:00
user_namespace.c proc: constify seq_operations 2014-08-08 15:57:22 -07:00
utsname.c namespaces: Use task_lock and not rcu to protect nsproxy 2014-07-29 18:08:50 -07:00
utsname_sysctl.c sysctl: convert use of typedef ctl_table to struct ctl_table 2014-06-06 16:08:16 -07:00
watchdog.c panic: add TAINT_SOFTLOCKUP 2014-08-08 15:57:24 -07:00
workqueue.c Merge branch 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-08-04 10:09:27 -07:00
workqueue_internal.h
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