user/sven/linux.git/kernel, branch v3.10.88

perf: Fix fasync handling on inherited events

2015-09-13T16:07:59Z

commit fed66e2cdd4f127a43fd11b8d92a99bdd429528c upstream. Vince reported that the fasync signal stuff doesn't work proper for inherited events. So fix that. Installing fasync allocates memory and sets filp->f_flags |= FASYNC, which upon the demise of the file descriptor ensures the allocation is freed and state is updated. Now for perf, we can have the events stick around for a while after the original FD is dead because of references from child events. So we cannot copy the fasync pointer around. We can however consistently use the parent's fasync, as that will be updated. Reported-and-Tested-by: Vince Weaver Signed-off-by: Peter Zijlstra (Intel) Cc: Arnaldo Carvalho deMelo Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: eranian@google.com Link: http://lkml.kernel.org/r/1434011521.1495.71.camel@twins Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

signal: fix information leak in copy_siginfo_from_user32

2015-08-17T03:51:42Z

commit 3c00cb5e68dc719f2fc73a33b1b230aadfcb1309 upstream. This function can leak kernel stack data when the user siginfo_t has a positive si_code value. The top 16 bits of si_code descibe which fields in the siginfo_t union are active, but they are treated inconsistently between copy_siginfo_from_user32, copy_siginfo_to_user32 and copy_siginfo_to_user. copy_siginfo_from_user32 is called from rt_sigqueueinfo and rt_tgsigqueueinfo in which the user has full control overthe top 16 bits of si_code. This fixes the following information leaks: x86: 8 bytes leaked when sending a signal from a 32-bit process to itself. This leak grows to 16 bytes if the process uses x32. (si_code = __SI_CHLD) x86: 100 bytes leaked when sending a signal from a 32-bit process to a 64-bit process. (si_code = -1) sparc: 4 bytes leaked when sending a signal from a 32-bit process to a 64-bit process. (si_code = any) parsic and s390 have similar bugs, but they are not vulnerable because rt_[tg]sigqueueinfo have checks that prevent sending a positive si_code to a different process. These bugs are also fixed for consistency. Signed-off-by: Amanieu d'Antras Cc: Oleg Nesterov Cc: Ingo Molnar Cc: Russell King Cc: Ralf Baechle Cc: Benjamin Herrenschmidt Cc: Chris Metcalf Cc: Paul Mackerras Cc: Michael Ellerman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

signal: fix information leak in copy_siginfo_to_user

2015-08-17T03:51:42Z

commit 26135022f85105ad725cda103fa069e29e83bd16 upstream. This function may copy the si_addr_lsb, si_lower and si_upper fields to user mode when they haven't been initialized, which can leak kernel stack data to user mode. Just checking the value of si_code is insufficient because the same si_code value is shared between multiple signals. This is solved by checking the value of si_signo in addition to si_code. Signed-off-by: Amanieu d'Antras Cc: Oleg Nesterov Cc: Ingo Molnar Cc: Russell King Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

genirq: Prevent resend to interrupts marked IRQ_NESTED_THREAD

2015-08-10T19:20:30Z

commit 75a06189fc508a2acf470b0b12710362ffb2c4b1 upstream. The resend mechanism happily calls the interrupt handler of interrupts which are marked IRQ_NESTED_THREAD from softirq context. This can result in crashes because the interrupt handler is not the proper way to invoke the device handlers. They must be invoked via handle_nested_irq. Prevent the resend even if the interrupt has no valid parent irq set. Its better to have a lost interrupt than a crashing machine. Reported-by: Uwe Kleine-König Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

tracing: Have branch tracer use recursive field of task struct

2015-08-03T16:29:45Z

commit 6224beb12e190ff11f3c7d4bf50cb2922878f600 upstream. Fengguang Wu's tests triggered a bug in the branch tracer's start up test when CONFIG_DEBUG_PREEMPT set. This was because that config adds some debug logic in the per cpu field, which calls back into the branch tracer. The branch tracer has its own recursive checks, but uses a per cpu variable to implement it. If retrieving the per cpu variable calls back into the branch tracer, you can see how things will break. Instead of using a per cpu variable, use the trace_recursion field of the current task struct. Simply set a bit when entering the branch tracing and clear it when leaving. If the bit is set on entry, just don't do the tracing. There's also the case with lockdep, as the local_irq_save() called before the recursion can also trigger code that can call back into the function. Changing that to a raw_local_irq_save() will protect that as well. This prevents the recursion and the inevitable crash that follows. Link: http://lkml.kernel.org/r/20150630141803.GA28071@wfg-t540p.sh.intel.com Reported-by: Fengguang Wu Tested-by: Fengguang Wu Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman

tracing/filter: Do not allow infix to exceed end of string

2015-08-03T16:29:45Z

commit 6b88f44e161b9ee2a803e5b2b1fbcf4e20e8b980 upstream. While debugging a WARN_ON() for filtering, I found that it is possible for the filter string to be referenced after its end. With the filter: # echo '>' > /sys/kernel/debug/events/ext4/ext4_truncate_exit/filter The filter_parse() function can call infix_get_op() which calls infix_advance() that updates the infix filter pointers for the cnt and tail without checking if the filter is already at the end, which will put the cnt to zero and the tail beyond the end. The loop then calls infix_next() that has ps->infix.cnt--; return ps->infix.string[ps->infix.tail++]; The cnt will now be below zero, and the tail that is returned is already passed the end of the filter string. So far the allocation of the filter string usually has some buffer that is zeroed out, but if the filter string is of the exact size of the allocated buffer there's no guarantee that the charater after the nul terminating character will be zero. Luckily, only root can write to the filter. Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman

tracing/filter: Do not WARN on operand count going below zero

2015-08-03T16:29:45Z

commit b4875bbe7e68f139bd3383828ae8e994a0df6d28 upstream. When testing the fix for the trace filter, I could not come up with a scenario where the operand count goes below zero, so I added a WARN_ON_ONCE(cnt < 0) to the logic. But there is legitimate case that it can happen (although the filter would be wrong). # echo '>' > /sys/kernel/debug/events/ext4/ext4_truncate_exit/filter That is, a single operation without any operands will hit the path where the WARN_ON_ONCE() can trigger. Although this is harmless, and the filter is reported as a error. But instead of spitting out a warning to the kernel dmesg, just fail nicely and report it via the proper channels. Link: http://lkml.kernel.org/r/558C6082.90608@oracle.com Reported-by: Vince Weaver Reported-by: Sasha Levin Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman

__ptrace_may_access() should not deny sub-threads

2015-07-04T02:48:08Z

commit 73af963f9f3036dffed55c3a2898598186db1045 upstream. __ptrace_may_access() checks get_dumpable/ptrace_has_cap/etc if task != current, this can can lead to surprising results. For example, a sub-thread can't readlink("/proc/self/exe") if the executable is not readable. setup_new_exec()->would_dump() notices that inode_permission(MAY_READ) fails and then it does set_dumpable(suid_dumpable). After that get_dumpable() fails. (It is not clear why proc_pid_readlink() checks get_dumpable(), perhaps we could add PTRACE_MODE_NODUMPABLE) Change __ptrace_may_access() to use same_thread_group() instead of "task == current". Any security check is pointless when the tasks share the same ->mm. Signed-off-by: Mark Grondona Signed-off-by: Ben Woodard Signed-off-by: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

tracing: Have filter check for balanced ops

2015-06-29T19:08:34Z

commit 2cf30dc180cea808077f003c5116388183e54f9e upstream. When the following filter is used it causes a warning to trigger: # cd /sys/kernel/debug/tracing # echo "((dev==1)blocks==2)" > events/ext4/ext4_truncate_exit/filter -bash: echo: write error: Invalid argument # cat events/ext4/ext4_truncate_exit/filter ((dev==1)blocks==2) ^ parse_error: No error ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1223 at kernel/trace/trace_events_filter.c:1640 replace_preds+0x3c5/0x990() Modules linked in: bnep lockd grace bluetooth ... CPU: 3 PID: 1223 Comm: bash Tainted: G W 4.1.0-rc3-test+ #450 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012 0000000000000668 ffff8800c106bc98 ffffffff816ed4f9 ffff88011ead0cf0 0000000000000000 ffff8800c106bcd8 ffffffff8107fb07 ffffffff8136b46c ffff8800c7d81d48 ffff8800d4c2bc00 ffff8800d4d4f920 00000000ffffffea Call Trace: [] dump_stack+0x4c/0x6e [] warn_slowpath_common+0x97/0xe0 [] ? _kstrtoull+0x2c/0x80 [] warn_slowpath_null+0x1a/0x20 [] replace_preds+0x3c5/0x990 [] create_filter+0x82/0xb0 [] apply_event_filter+0xd4/0x180 [] event_filter_write+0x8f/0x120 [] __vfs_write+0x28/0xe0 [] ? __sb_start_write+0x53/0xf0 [] ? security_file_permission+0x30/0xc0 [] vfs_write+0xb8/0x1b0 [] SyS_write+0x4f/0xb0 [] system_call_fastpath+0x12/0x6a ---[ end trace e11028bd95818dcd ]--- Worse yet, reading the error message (the filter again) it says that there was no error, when there clearly was. The issue is that the code that checks the input does not check for balanced ops. That is, having an op between a closed parenthesis and the next token. This would only cause a warning, and fail out before doing any real harm, but it should still not caues a warning, and the error reported should work: # cd /sys/kernel/debug/tracing # echo "((dev==1)blocks==2)" > events/ext4/ext4_truncate_exit/filter -bash: echo: write error: Invalid argument # cat events/ext4/ext4_truncate_exit/filter ((dev==1)blocks==2) ^ parse_error: Meaningless filter expression And give no kernel warning. Link: http://lkml.kernel.org/r/20150615175025.7e809215@gandalf.local.home Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Reported-by: Vince Weaver Tested-by: Vince Weaver Signed-off-by: Steven Rostedt [ luis: backported to 3.16: - unconditionally decrement cnt as the OP_NOT logic was introduced only by e12c09cf3087 ("tracing: Add NOT to filtering logic") ] Signed-off-by: Luis Henriques Signed-off-by: Greg Kroah-Hartman

ring-buffer-benchmark: Fix the wrong sched_priority of producer

2015-06-22T23:55:53Z

commit 108029323910c5dd1ef8fa2d10da1ce5fbce6e12 upstream. The producer should be used producer_fifo as its sched_priority, so correct it. Link: http://lkml.kernel.org/r/1433923957-67842-1-git-send-email-long.wanglong@huawei.com Signed-off-by: Wang Long Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman