Linus Torvalds e4178d809f printk: fix syslog() overflowing user buffer ... This is not a buffer overflow in the traditional sense: we don't overflow any *kernel* buffers, but we do mis-count the amount of data we copy back to user space for the SYSLOG_ACTION_READ_ALL case. In particular, if the user buffer is too small to hold everything, and *if* there is a continuation line at just the right place, we can end up giving the user more data than he asked for. The reason is that we first count up the number of bytes all the log records contains, then we walk the records again until we've skipped the records at the beginning that won't fit, and then we walk the rest of the records and copy them to the user space buffer. And in between that "skip the initial records that won't fit" and the "copy the records that *will* fit to user space", we reset the 'prev' variable that contained the record information for the last record not copied. That meant that when we started copying to user space, we now had a different character count than what we had originally calculated in the first record walk-through. The fix is to simply not clear the 'prev' flags value (in both cases where we had the same logic: syslog_print_all and kmsg_dump_get_buffer: the latter is used for pstore-like dumping) Reported-and-tested-by: Debabrata Banerjee <dbanerje@akamai.com> Acked-by: Kay Sievers <kay@vrfy.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2014-02-17 12:24:45 -08:00
..
cpu	sched/preempt: Fix up missed PREEMPT_NEED_RESCHED folding	2014-01-13 17:38:55 +01:00
debug	kgdb/kdb: Fix no KDB config problem	2014-01-25 08:55:09 +01:00
events	This pull request has a new feature to ftrace, namely the trace event	2014-01-22 16:35:21 -08:00
gcov	gcov: reuse kbasename helper	2013-11-13 12:09:34 +09:00
irq	Merge branches 'irq-urgent-for-linus' and 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-02-15 16:06:12 -08:00
locking	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-01-20 10:42:08 -08:00
power	Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block	2014-01-30 11:19:05 -08:00
printk	printk: fix syslog() overflowing user buffer	2014-02-17 12:24:45 -08:00
rcu	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2014-01-28 08:38:04 -08:00
sched	Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-01-31 09:02:51 -08:00
time	tick: Clear broadcast pending bit when switching to oneshot	2014-02-13 21:55:54 +01:00
trace	ring-buffer: Fix first commit on sub-buffer having non-zero delta	2014-02-11 13:38:54 -05:00
.gitignore	Ignore generated file kernel/x509_certificate_list	2013-12-10 18:21:34 +00:00
acct.c
async.c
audit_tree.c	fsnotify: remove pointless NULL initializers	2014-01-21 16:19:41 -08:00
audit_watch.c	fsnotify: remove pointless NULL initializers	2014-01-21 16:19:41 -08:00
audit.c	audit: fix location of __net_initdata for audit_net_ops	2014-01-17 17:14:32 -05:00
audit.h	audit: Convert int limit uses to u32	2014-01-14 14:54:00 -05:00
auditfilter.c	audit: log on errors from filter user rules	2014-01-13 22:32:31 -05:00
auditsc.c	execve: use 'struct filename *' for executable name passing	2014-02-05 12:54:53 -08:00
backtracetest.c
bounds.c	mm: do not allocate page->ptl dynamically, if spinlock_t fits to long	2013-12-20 12:25:45 -08:00
capability.c	audit: Simplify and correct audit_log_capset	2014-01-13 22:26:48 -05:00
cgroup_freezer.c	cgroup: replace cftype->read_seq_string() with cftype->seq_show()	2013-12-05 12:28:04 -05:00
cgroup.c	Merge branch 'for-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2014-01-21 17:51:34 -08:00
compat.c
configs.c
context_tracking.c	context_tracking: Wrap static key check into more intuitive function name	2013-12-02 20:43:14 +01:00
cpu_pm.c
cpu.c	Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2013-11-14 16:55:11 +09:00
cpuset.c	cgroup: replace cftype->read_seq_string() with cftype->seq_show()	2013-12-05 12:28:04 -05:00
crash_dump.c
cred.c
delayacct.c	kernel/delayacct.c: remove redundant checking in __delayacct_add_tsk()	2013-11-13 12:09:12 +09:00
dma.c
elfcore.c	switch elf_core_write_extra_phdrs() to dump_emit()	2013-11-09 00:16:23 -05:00
exec_domain.c
exit.c	introduce for_each_thread() to replace the buggy while_each_thread()	2014-01-21 16:19:46 -08:00
extable.c	kernel/extable: fix address-checks for core_kernel and init areas	2013-11-28 09:49:41 -08:00
fork.c	exec: kill task_struct->did_exec	2014-01-23 16:37:02 -08:00
freezer.c	libata, freezer: avoid block device removal while system is frozen	2013-12-19 13:50:32 -05:00
futex_compat.c
futex.c	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-01-20 10:42:08 -08:00
groups.c	userns: Kill nsown_capable it makes the wrong thing easy	2013-08-30 23:44:11 -07:00
hrtimer.c	sched/deadline: Add SCHED_DEADLINE structures & implementation	2014-01-13 13:41:06 +01:00
hung_task.c	hung_task: Display every hung task warning	2014-01-25 12:13:33 +01:00
irq_work.c
itimer.c
jump_label.c	static_key: WARN on usage before jump_label_init was called	2013-10-19 19:45:35 -04:00
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz	kernel: remove CONFIG_USE_GENERIC_SMP_HELPERS	2013-11-15 09:32:22 +09:00
Kconfig.locks
Kconfig.preempt
kexec.c	kernel/kexec.c: use vscnprintf() instead of vsnprintf() in vmcoreinfo_append_str()	2014-01-27 21:02:40 -08:00
kmod.c	execve: use 'struct filename *' for executable name passing	2014-02-05 12:54:53 -08:00
kprobes.c	kprobes: use KSYM_NAME_LEN to size identifier buffers	2013-11-13 12:09:26 +09:00
ksysfs.c	kdump: fix exported size of vmcoreinfo note	2014-01-23 16:37:03 -08:00
kthread.c	kthread: make kthread_create() killable	2013-11-13 12:08:59 +09:00
latencytop.c
Makefile	KEYS: Remove files generated when SYSTEM_TRUSTED_KEYRING=y	2013-12-13 15:59:11 +00:00
module_signing.c	keys: change asymmetric keys to use common hash definitions	2013-10-25 17:15:18 -04:00
module-internal.h	KEYS: Separate the kernel signature checking keyring from module signing	2013-09-25 17:17:01 +01:00
module.c	module: Add missing newline in printk call.	2014-01-21 09:59:16 +10:30
notifier.c
nsproxy.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2013-09-07 14:35:32 -07:00
padata.c	padata: Fix wrong usage of rcu_dereference()	2013-12-05 21:28:42 +08:00
panic.c	panic: Make panic_timeout configurable	2013-11-26 12:12:26 +01:00
params.c	params: improve standard definitions	2013-12-04 14:09:46 +10:30
pid_namespace.c	pid_namespace: make freeing struct pid_namespace rcu-delayed	2013-10-24 23:43:29 -04:00
pid.c	pidns: fix free_pid() to handle the first fork failure	2013-09-30 14:31:03 -07:00
posix-cpu-timers.c	posix-timers: Convert abuses of BUG_ON to WARN_ON	2013-12-09 16:56:29 +01:00
posix-timers.c
profile.c	kernel: delete __cpuinit usage from all core kernel files	2013-07-14 19:36:59 -04:00
ptrace.c	exec/ptrace: fix get_dumpable() incorrect tests	2013-11-13 12:09:33 +09:00
range.c	range: Do not add new blank slot with add_range_with_merge	2013-06-18 11:32:10 -05:00
reboot.c	kexec: migrate to reboot cpu	2013-12-18 19:04:50 -08:00
relay.c	kernel: delete __cpuinit usage from all core kernel files	2013-07-14 19:36:59 -04:00
res_counter.c	memcg: reduce function dereference	2013-09-12 15:38:02 -07:00
resource.c	kernel/resource.c: remove the unneeded assignment in function __find_resource	2013-07-03 16:08:06 -07:00
seccomp.c
signal.c	kernel/signal.c: change do_signal_stop/do_sigaction to use while_each_thread()	2014-01-23 16:37:02 -08:00
smp.c	kernel/smp.c: remove cpumask_ipi	2014-01-30 16:56:54 -08:00
smpboot.c	kernel: delete __cpuinit usage from all core kernel files	2013-07-14 19:36:59 -04:00
smpboot.h
softirq.c	Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-01-31 09:02:51 -08:00
stacktrace.c
stop_machine.c	stop_machine: Fix race between stop_two_cpus() and stop_cpus()	2013-11-11 12:43:38 +01:00
sys_ni.c
sys.c	kernel/sys.c: k_getrusage() can use while_each_thread()	2014-01-23 16:37:02 -08:00
sysctl_binary.c	kernel/sysctl_binary.c: use scnprintf() instead of snprintf()	2013-11-13 12:09:33 +09:00
sysctl.c	Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-01-31 08:59:46 -08:00
system_certificates.S	KEYS: correct alignment of system_certificate_list content in assembly file	2013-12-10 18:25:28 +00:00
system_keyring.c	KEYS: correct alignment of system_certificate_list content in assembly file	2013-12-10 18:25:28 +00:00
task_work.c	task_work: documentation	2013-09-11 15:58:27 -07:00
taskstats.c	genetlink: only pass array to genl_register_family_with_ops()	2013-11-19 16:39:05 -05:00
test_kprobes.c
time.c	sched: Rename sched.c as sched/core.c in comments and Documentation	2013-06-19 12:58:42 +02:00
timeconst.bc
timer.c	timer: Convert kmalloc_node(...GFP_ZERO...) to kzalloc_node(...)	2013-11-19 14:59:50 +01:00
tracepoint.c
tsacct.c
uid16.c	userns: Kill nsown_capable it makes the wrong thing easy	2013-08-30 23:44:11 -07:00
up.c	kernel: provide a __smp_call_function_single stub for !CONFIG_SMP	2013-11-15 09:32:22 +09:00
user_namespace.c	KEYS: Add per-user_namespace registers for persistent per-UID kerberos caches	2013-09-24 10:35:19 +01:00
user-return-notifier.c
user.c	KEYS: fix uninitialized persistent_keyring_register_sem	2013-12-13 15:59:11 +00:00
utsname_sysctl.c
utsname.c	userns: Kill nsown_capable it makes the wrong thing easy	2013-08-30 23:44:11 -07:00
watchdog.c	watchdog: update watchdog_thresh properly	2013-09-24 17:00:25 -07:00
workqueue_internal.h	sched: Rename sched.c as sched/core.c in comments and Documentation	2013-06-19 12:58:42 +02:00
workqueue.c	Merge branch 'for-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq	2014-01-21 17:46:31 -08:00