kernel/linux.git, branch v3.18.139

Linux 3.18.139

2019-04-27T07:30:31+00:00

kernel/sysctl.c: fix out-of-bounds access when setting file-max

2019-04-27T07:30:31+00:00

commit 9002b21465fa4d829edfc94a5a441005cffaa972 upstream. Commit 32a5ad9c2285 ("sysctl: handle overflow for file-max") hooked up min/max values for the file-max sysctl parameter via the .extra1 and .extra2 fields in the corresponding struct ctl_table entry. Unfortunately, the minimum value points at the global 'zero' variable, which is an int. This results in a KASAN splat when accessed as a long by proc_doulongvec_minmax on 64-bit architectures: | BUG: KASAN: global-out-of-bounds in __do_proc_doulongvec_minmax+0x5d8/0x6a0 | Read of size 8 at addr ffff2000133d1c20 by task systemd/1 | | CPU: 0 PID: 1 Comm: systemd Not tainted 5.1.0-rc3-00012-g40b114779944 #2 | Hardware name: linux,dummy-virt (DT) | Call trace: | dump_backtrace+0x0/0x228 | show_stack+0x14/0x20 | dump_stack+0xe8/0x124 | print_address_description+0x60/0x258 | kasan_report+0x140/0x1a0 | __asan_report_load8_noabort+0x18/0x20 | __do_proc_doulongvec_minmax+0x5d8/0x6a0 | proc_doulongvec_minmax+0x4c/0x78 | proc_sys_call_handler.isra.19+0x144/0x1d8 | proc_sys_write+0x34/0x58 | __vfs_write+0x54/0xe8 | vfs_write+0x124/0x3c0 | ksys_write+0xbc/0x168 | __arm64_sys_write+0x68/0x98 | el0_svc_common+0x100/0x258 | el0_svc_handler+0x48/0xc0 | el0_svc+0x8/0xc | | The buggy address belongs to the variable: | zero+0x0/0x40 | | Memory state around the buggy address: | ffff2000133d1b00: 00 00 00 00 00 00 00 00 fa fa fa fa 04 fa fa fa | ffff2000133d1b80: fa fa fa fa 04 fa fa fa fa fa fa fa 04 fa fa fa | >ffff2000133d1c00: fa fa fa fa 04 fa fa fa fa fa fa fa 00 00 00 00 | ^ | ffff2000133d1c80: fa fa fa fa 00 fa fa fa fa fa fa fa 00 00 00 00 | ffff2000133d1d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 Fix the splat by introducing a unsigned long 'zero_ul' and using that instead. Link: http://lkml.kernel.org/r/20190403153409.17307-1-will.deacon@arm.com Fixes: 32a5ad9c2285 ("sysctl: handle overflow for file-max") Signed-off-by: Will Deacon Acked-by: Christian Brauner Cc: Kees Cook Cc: Alexey Dobriyan Cc: Matteo Croce Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

arm64: futex: Restore oldval initialization to work around buggy compilers

2019-04-27T07:30:31+00:00

commit ff8acf929014b7f87315588e0daf8597c8aa9d1c upstream. Commit 045afc24124d ("arm64: futex: Fix FUTEX_WAKE_OP atomic ops with non-zero result value") removed oldval's zero initialization in arch_futex_atomic_op_inuser because it is not necessary. Unfortunately, Android's arm64 GCC 4.9.4 [1] does not agree: ../kernel/futex.c: In function 'do_futex': ../kernel/futex.c:1658:17: warning: 'oldval' may be used uninitialized in this function [-Wmaybe-uninitialized] return oldval == cmparg; ^ In file included from ../kernel/futex.c:73:0: ../arch/arm64/include/asm/futex.h:53:6: note: 'oldval' was declared here int oldval, ret, tmp; ^ GCC fails to follow that when ret is non-zero, futex_atomic_op_inuser returns right away, avoiding the uninitialized use that it claims. Restoring the zero initialization works around this issue. [1]: https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9/ Cc: stable@vger.kernel.org Fixes: 045afc24124d ("arm64: futex: Fix FUTEX_WAKE_OP atomic ops with non-zero result value") Reviewed-by: Greg Kroah-Hartman Signed-off-by: Nathan Chancellor Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman

device_cgroup: fix RCU imbalance in error case

2019-04-27T07:30:31+00:00

commit 0fcc4c8c044e117ac126ab6df4138ea9a67fa2a9 upstream. When dev_exception_add() returns an error (due to a failed memory allocation), make sure that we move the RCU preemption count back to where it was before we were called. We dropped the RCU read lock inside the loop body, so we can't just "break". sparse complains about this, too: $ make -s C=2 security/device_cgroup.o ./include/linux/rcupdate.h:647:9: warning: context imbalance in 'propagate_exception' - unexpected unlock Fixes: d591fb56618f ("device_cgroup: simplify cgroup tree walk in propagate_exception()") Cc: stable@vger.kernel.org Signed-off-by: Jann Horn Acked-by: Michal Hocko Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman

sched/fair: Limit sched_cfs_period_timer() loop to avoid hard lockup

2019-04-27T07:30:31+00:00

[ Upstream commit 2e8e19226398db8265a8e675fcc0118b9e80c9e8 ] With extremely short cfs_period_us setting on a parent task group with a large number of children the for loop in sched_cfs_period_timer() can run until the watchdog fires. There is no guarantee that the call to hrtimer_forward_now() will ever return 0. The large number of children can make do_sched_cfs_period_timer() take longer than the period. NMI watchdog: Watchdog detected hard LOCKUP on cpu 24 RIP: 0010:tg_nop+0x0/0x10 walk_tg_tree_from+0x29/0xb0 unthrottle_cfs_rq+0xe0/0x1a0 distribute_cfs_runtime+0xd3/0xf0 sched_cfs_period_timer+0xcb/0x160 ? sched_cfs_slack_timer+0xd0/0xd0 __hrtimer_run_queues+0xfb/0x270 hrtimer_interrupt+0x122/0x270 smp_apic_timer_interrupt+0x6a/0x140 apic_timer_interrupt+0xf/0x20 To prevent this we add protection to the loop that detects when the loop has run too many times and scales the period and quota up, proportionally, so that the timer can complete before then next period expires. This preserves the relative runtime quota while preventing the hard lockup. A warning is issued reporting this state and the new values. Signed-off-by: Phil Auld Signed-off-by: Peter Zijlstra (Intel) Cc: Cc: Anton Blanchard Cc: Ben Segall Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: https://lkml.kernel.org/r/20190319130005.25492-1-pauld@redhat.com Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin

kprobes: Fix error check when reusing optimized probes

2019-04-27T07:30:31+00:00

commit 5f843ed415581cfad4ef8fefe31c138a8346ca8a upstream. The following commit introduced a bug in one of our error paths: 819319fc9346 ("kprobes: Return error if we fail to reuse kprobe instead of BUG_ON()") it missed to handle the return value of kprobe_optready() as error-value. In reality, the kprobe_optready() returns a bool result, so "true" case must be passed instead of 0. This causes some errors on kprobe boot-time selftests on ARM: [ ] Beginning kprobe tests... [ ] Probe ARM code [ ] kprobe [ ] kretprobe [ ] ARM instruction simulation [ ] Check decoding tables [ ] Run test cases [ ] FAIL: test_case_handler not run [ ] FAIL: Test andge r10, r11, r14, asr r7 [ ] FAIL: Scenario 11 ... [ ] FAIL: Scenario 7 [ ] Total instruction simulation tests=1631, pass=1433 fail=198 [ ] kprobe tests failed This can happen if an optimized probe is unregistered and next kprobe is registered on same address until the previous probe is not reclaimed. If this happens, a hidden aggregated probe may be kept in memory, and no new kprobe can probe same address. Also, in that case register_kprobe() will return "1" instead of minus error value, which can mislead caller logic. Signed-off-by: Masami Hiramatsu Cc: Anil S Keshavamurthy Cc: David S . Miller Cc: Linus Torvalds Cc: Naveen N . Rao Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: stable@vger.kernel.org # v5.0+ Fixes: 819319fc9346 ("kprobes: Return error if we fail to reuse kprobe instead of BUG_ON()") Link: http://lkml.kernel.org/r/155530808559.32517.539898325433642204.stgit@devnote2 Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

x86/kprobes: Verify stack frame on kretprobe

2019-04-27T07:30:30+00:00

commit 3ff9c075cc767b3060bdac12da72fc94dd7da1b8 upstream. Verify the stack frame pointer on kretprobe trampoline handler, If the stack frame pointer does not match, it skips the wrong entry and tries to find correct one. This can happen if user puts the kretprobe on the function which can be used in the path of ftrace user-function call. Such functions should not be probed, so this adds a warning message that reports which function should be blacklisted. Tested-by: Andrea Righi Signed-off-by: Masami Hiramatsu Acked-by: Steven Rostedt Cc: Linus Torvalds Cc: Mathieu Desnoyers Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/155094059185.6137.15527904013362842072.stgit@devbox Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

ALSA: core: Fix card races between register and disconnect

2019-04-27T07:30:30+00:00

commit 2a3f7221acddfe1caa9ff09b3a8158c39b2fdeac upstream. There is a small race window in the card disconnection code that allows the registration of another card with the very same card id. This leads to a warning in procfs creation as caught by syzkaller. The problem is that we delete snd_cards and snd_cards_lock entries at the very beginning of the disconnection procedure. This makes the slot available to be assigned for another card object while the disconnection procedure is being processed. Then it becomes possible to issue a procfs registration with the existing file name although we check the conflict beforehand. The fix is simply to move the snd_cards and snd_cards_lock clearances at the end of the disconnection procedure. The references to these entries are merely either from the global proc files like /proc/asound/cards or from the card registration / disconnection, so it should be fine to shift at the very end. Reported-by: syzbot+48df349490c36f9f54ab@syzkaller.appspotmail.com Cc: Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman

staging: comedi: ni_usb6501: Fix possible double-free of ->usb_rx_buf

2019-04-27T07:30:30+00:00

commit af4b54a2e5ba18259ff9aac445bf546dd60d037e upstream. `ni6501_alloc_usb_buffers()` is called from `ni6501_auto_attach()` to allocate RX and TX buffers for USB transfers. It allocates `devpriv->usb_rx_buf` followed by `devpriv->usb_tx_buf`. If the allocation of `devpriv->usb_tx_buf` fails, it frees `devpriv->usb_rx_buf`, leaving the pointer set dangling, and returns an error. Later, `ni6501_detach()` will be called from the core comedi module code to clean up. `ni6501_detach()` also frees both `devpriv->usb_rx_buf` and `devpriv->usb_tx_buf`, but `devpriv->usb_rx_buf` may have already beed freed, leading to a double-free error. Fix it bu removing the call to `kfree(devpriv->usb_rx_buf)` from `ni6501_alloc_usb_buffers()`, relying on `ni6501_detach()` to free the memory. Signed-off-by: Ian Abbott Cc: stable Signed-off-by: Greg Kroah-Hartman

staging: comedi: vmk80xx: Fix possible double-free of ->usb_rx_buf

2019-04-27T07:30:30+00:00

commit 663d294b4768bfd89e529e069bffa544a830b5bf upstream. `vmk80xx_alloc_usb_buffers()` is called from `vmk80xx_auto_attach()` to allocate RX and TX buffers for USB transfers. It allocates `devpriv->usb_rx_buf` followed by `devpriv->usb_tx_buf`. If the allocation of `devpriv->usb_tx_buf` fails, it frees `devpriv->usb_rx_buf`, leaving the pointer set dangling, and returns an error. Later, `vmk80xx_detach()` will be called from the core comedi module code to clean up. `vmk80xx_detach()` also frees both `devpriv->usb_rx_buf` and `devpriv->usb_tx_buf`, but `devpriv->usb_rx_buf` may have already been freed, leading to a double-free error. Fix it by removing the call to `kfree(devpriv->usb_rx_buf)` from `vmk80xx_alloc_usb_buffers()`, relying on `vmk80xx_detach()` to free the memory. Signed-off-by: Ian Abbott Cc: stable Signed-off-by: Greg Kroah-Hartman