Commit Graph

46029 Commits

Author SHA1 Message Date
Linus Torvalds
4a5df37964 Merge tag 'mm-hotfixes-stable-2024-11-16-15-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull hotfixes from Andrew Morton:
 "10 hotfixes, 7 of which are cc:stable. All singletons, please see the
  changelogs for details"

* tag 'mm-hotfixes-stable-2024-11-16-15-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm: revert "mm: shmem: fix data-race in shmem_getattr()"
  ocfs2: uncache inode which has failed entering the group
  mm: fix NULL pointer dereference in alloc_pages_bulk_noprof
  mm, doc: update read_ahead_kb for MADV_HUGEPAGE
  fs/proc/task_mmu: prevent integer overflow in pagemap_scan_get_args()
  sched/task_stack: fix object_is_on_stack() for KASAN tagged pointers
  crash, powerpc: default to CRASH_DUMP=n on PPC_BOOK3S_32
  mm/mremap: fix address wraparound in move_page_tables()
  tools/mm: fix compile error
  mm, swap: fix allocation and scanning race with swapoff
2024-11-16 16:00:38 -08:00
Linus Torvalds
b5a24181e4 Merge tag 'trace-ringbuffer-v6.12-rc7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ring buffer fixes from Steven Rostedt:

 - Revert: "ring-buffer: Do not have boot mapped buffers hook to CPU
   hotplug"

   A crash that happened on cpu hotplug was actually caused by the
   incorrect ref counting that was fixed by commit 2cf9733891
   ("ring-buffer: Fix refcount setting of boot mapped buffers"). The
   removal of calling cpu hotplug callbacks on memory mapped buffers was
   not an issue even though the tests at the time pointed toward it. But
   in fact, there's a check in that code that tests to see if the
   buffers are already allocated or not, and will not allocate them
   again if they are. Not calling the cpu hotplug callbacks ended up not
   initializing the non boot CPU buffers.

   Simply remove that change.

 - Clear all CPU buffers when starting tracing in a boot mapped buffer

   To properly process events from a previous boot, the address space
   needs to be accounted for due to KASLR and the events in the buffer
   are updated accordingly when read. This also requires that when the
   buffer has tracing enabled again in the current boot that the buffers
   are reset so that events from the previous boot do not interact with
   the events of the current boot and cause confusing due to not having
   the proper meta data.

   It was found that if a CPU is taken offline, that its per CPU buffer
   is not reset when tracing starts. This allows for events to be from
   both the previous boot and the current boot to be in the buffer at
   the same time. Clear all CPU buffers when tracing is started in a
   boot mapped buffer.

* tag 'trace-ringbuffer-v6.12-rc7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/ring-buffer: Clear all memory mapped CPU ring buffers on first recording
  Revert: "ring-buffer: Do not have boot mapped buffers hook to CPU hotplug"
2024-11-16 08:12:43 -08:00
Linus Torvalds
d79944b094 Merge tag 'sched_ext-for-6.12-rc7-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext
Pull sched_ext fix from Tejun Heo:
 "One more fix for v6.12-rc7

  ops.cpu_acquire() was being invoked with the wrong kfunc mask allowing
  the operation to call kfuncs which shouldn't be allowed. Fix it by
  using SCX_KF_REST instead, which is trivial and low risk"

* tag 'sched_ext-for-6.12-rc7-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
  sched_ext: ops.cpu_acquire() should be called with SCX_KF_REST
2024-11-15 09:59:51 -08:00
Dave Vasilevsky
31daa34315 crash, powerpc: default to CRASH_DUMP=n on PPC_BOOK3S_32
Fixes boot failures on 6.9 on PPC_BOOK3S_32 machines using Open Firmware. 
On these machines, the kernel refuses to boot from non-zero
PHYSICAL_START, which occurs when CRASH_DUMP is on.

Since most PPC_BOOK3S_32 machines boot via Open Firmware, it should
default to off for them.  Users booting via some other mechanism can still
turn it on explicitly.

Does not change the default on any other architectures for the
time being.

Link: https://lkml.kernel.org/r/20240917163720.1644584-1-dave@vasilevsky.ca
Fixes: 75bc255a74 ("crash: clean up kdump related config items")
Signed-off-by: Dave Vasilevsky <dave@vasilevsky.ca>
Reported-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
Closes: https://lists.debian.org/debian-powerpc/2024/07/msg00001.html
Acked-by: Michael Ellerman <mpe@ellerman.id.au>	[powerpc]
Acked-by: Baoquan He <bhe@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-14 22:43:48 -08:00
Tejun Heo
a4af89cc50 sched_ext: ops.cpu_acquire() should be called with SCX_KF_REST
ops.cpu_acquire() is currently called with 0 kf_maks which is interpreted as
SCX_KF_UNLOCKED which allows all unlocked kfuncs, but ops.cpu_acquire() is
called from balance_one() under the rq lock and should only be allowed call
kfuncs that are safe under the rq lock. Update it to use SCX_KF_REST.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Vernet <void@manifault.com>
Cc: Zhao Mengmeng <zhaomzhao@126.com>
Link: http://lkml.kernel.org/r/ZzYvf2L3rlmjuKzh@slm.duckdns.org
Fixes: 245254f708 ("sched_ext: Implement sched_ext_ops.cpu_acquire/release()")
2024-11-14 08:50:58 -10:00
Steven Rostedt
09663753bb tracing/ring-buffer: Clear all memory mapped CPU ring buffers on first recording
The events of a memory mapped ring buffer from the previous boot should
not be mixed in with events from the current boot. There's meta data that
is used to handle KASLR so that function names can be shown properly.

Also, since the timestamps of the previous boot have no meaning to the
timestamps of the current boot, having them intermingled in a buffer can
also cause confusion because there could possibly be events in the future.

When a trace is activated the meta data is reset so that the pointers of
are now processed for the new address space. The trace buffers are reset
when tracing starts for the first time. The problem here is that the reset
only happens on online CPUs. If a CPU is offline, it does not get reset.

To demonstrate the issue, a previous boot had tracing enabled in the boot
mapped ring buffer on reboot. On the following boot, tracing has not been
started yet so the function trace from the previous boot is still visible.

 # trace-cmd show -B boot_mapped -c 3 | tail
          <idle>-0       [003] d.h2.   156.462395: __rcu_read_lock <-cpu_emergency_disable_virtualization
          <idle>-0       [003] d.h2.   156.462396: vmx_emergency_disable_virtualization_cpu <-cpu_emergency_disable_virtualization
          <idle>-0       [003] d.h2.   156.462396: __rcu_read_unlock <-__sysvec_reboot
          <idle>-0       [003] d.h2.   156.462397: stop_this_cpu <-__sysvec_reboot
          <idle>-0       [003] d.h2.   156.462397: set_cpu_online <-stop_this_cpu
          <idle>-0       [003] d.h2.   156.462397: disable_local_APIC <-stop_this_cpu
          <idle>-0       [003] d.h2.   156.462398: clear_local_APIC <-disable_local_APIC
          <idle>-0       [003] d.h2.   156.462574: mcheck_cpu_clear <-stop_this_cpu
          <idle>-0       [003] d.h2.   156.462575: mce_intel_feature_clear <-stop_this_cpu
          <idle>-0       [003] d.h2.   156.462575: lmce_supported <-mce_intel_feature_clear

Now, if CPU 3 is taken offline, and tracing is started on the memory
mapped ring buffer, the events from the previous boot in the CPU 3 ring
buffer is not reset. Now those events are using the meta data from the
current boot and produces just hex values.

 # echo 0 > /sys/devices/system/cpu/cpu3/online
 # trace-cmd start -B boot_mapped -p function
 # trace-cmd show -B boot_mapped -c 3 | tail
          <idle>-0       [003] d.h2.   156.462395: 0xffffffff9a1e3194 <-0xffffffff9a0f655e
          <idle>-0       [003] d.h2.   156.462396: 0xffffffff9a0a1d24 <-0xffffffff9a0f656f
          <idle>-0       [003] d.h2.   156.462396: 0xffffffff9a1e6bc4 <-0xffffffff9a0f7323
          <idle>-0       [003] d.h2.   156.462397: 0xffffffff9a0d12b4 <-0xffffffff9a0f732a
          <idle>-0       [003] d.h2.   156.462397: 0xffffffff9a1458d4 <-0xffffffff9a0d12e2
          <idle>-0       [003] d.h2.   156.462397: 0xffffffff9a0faed4 <-0xffffffff9a0d12e7
          <idle>-0       [003] d.h2.   156.462398: 0xffffffff9a0faaf4 <-0xffffffff9a0faef2
          <idle>-0       [003] d.h2.   156.462574: 0xffffffff9a0e3444 <-0xffffffff9a0d12ef
          <idle>-0       [003] d.h2.   156.462575: 0xffffffff9a0e4964 <-0xffffffff9a0d12ef
          <idle>-0       [003] d.h2.   156.462575: 0xffffffff9a0e3fb0 <-0xffffffff9a0e496f

Reset all CPUs when starting a boot mapped ring buffer for the first time,
and not just the online CPUs.

Fixes: 7a1d1e4b96 ("tracing/ring-buffer: Add last_boot_info file to boot instance")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-14 11:54:34 -05:00
Steven Rostedt
580bb355bc Revert: "ring-buffer: Do not have boot mapped buffers hook to CPU hotplug"
A crash happened when testing cpu hotplug with respect to the memory
mapped ring buffers. It was assumed that the hot plug code was adding a
per CPU buffer that was already created that caused the crash. The real
problem was due to ref counting and was fixed by commit 2cf9733891
("ring-buffer: Fix refcount setting of boot mapped buffers").

When a per CPU buffer is created, it will not be created again even with
CPU hotplug, so the fix to not use CPU hotplug was a red herring. In fact,
it caused only the boot CPU buffer to be created, leaving the other CPU
per CPU buffers disabled.

Revert that change as it was not the culprit of the fix it was intended to
be.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241113230839.6c03640f@gandalf.local.home
Fixes: 912da2c384 ("ring-buffer: Do not have boot mapped buffers hook to CPU hotplug")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-14 10:01:00 -05:00
Linus Torvalds
3022e9d00e Merge tag 'sched_ext-for-6.12-rc7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext
Pull sched_ext fixes from Tejun Heo:

 - The fair sched class currently has a bug where its balance() returns
   true telling the sched core that it has tasks to run but then NULL
   from pick_task(). This makes sched core call sched_ext's pick_task()
   without preceding balance() which can lead to stalls in partial mode.

   For now, work around by detecting the condition and forcing the CPU
   to go through another scheduling cycle.

 - Add a missing newline to an error message and fix drgn introspection
   tool which went out of sync.

* tag 'sched_ext-for-6.12-rc7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
  sched_ext: Handle cases where pick_task_scx() is called without preceding balance_scx()
  sched_ext: Update scx_show_state.py to match scx_ops_bypass_depth's new type
  sched_ext: Add a missing newline at the end of an error message
2024-11-11 14:09:57 -08:00
Linus Torvalds
28e43197c4 Merge tag 'mm-hotfixes-stable-2024-11-09-22-40' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
 "20 hotfixes, 14 of which are cc:stable.

  Three affect DAMON. Lorenzo's five-patch series to address the
  mmap_region error handling is here also.

  Apart from that, various singletons"

* tag 'mm-hotfixes-stable-2024-11-09-22-40' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mailmap: add entry for Thorsten Blum
  ocfs2: remove entry once instead of null-ptr-dereference in ocfs2_xa_remove()
  signal: restore the override_rlimit logic
  fs/proc: fix compile warning about variable 'vmcore_mmap_ops'
  ucounts: fix counter leak in inc_rlimit_get_ucounts()
  selftests: hugetlb_dio: check for initial conditions to skip in the start
  mm: fix docs for the kernel parameter ``thp_anon=``
  mm/damon/core: avoid overflow in damon_feed_loop_next_input()
  mm/damon/core: handle zero schemes apply interval
  mm/damon/core: handle zero {aggregation,ops_update} intervals
  mm/mlock: set the correct prev on failure
  objpool: fix to make percpu slot allocation more robust
  mm/page_alloc: keep track of free highatomic
  mm: resolve faulty mmap_region() error path behaviour
  mm: refactor arch_calc_vm_flag_bits() and arm64 MTE handling
  mm: refactor map_deny_write_exec()
  mm: unconditionally close VMAs on error
  mm: avoid unsafe VMA hook invocation when error arises on mmap hook
  mm/thp: fix deferred split unqueue naming and locking
  mm/thp: fix deferred split queue not partially_mapped
2024-11-10 09:04:27 -08:00
Tejun Heo
a6250aa251 sched_ext: Handle cases where pick_task_scx() is called without preceding balance_scx()
sched_ext dispatches tasks from the BPF scheduler from balance_scx() and
thus every pick_task_scx() call must be preceded by balance_scx(). While
this usually holds, due to a bug, there are cases where the fair class's
balance() returns true indicating that it has tasks to run on the CPU and
thus terminating balance() calls but fails to actually find the next task to
run when pick_task() is called. In such cases, pick_task_scx() can be called
without preceding balance_scx().

Detect this condition using SCX_RQ_BAL_PENDING flags. If detected, keep
running the previous task if possible and avoid stalling from entering idle
without balancing.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/Ztj_h5c2LYsdXYbA@slm.duckdns.org
2024-11-09 10:43:55 -10:00
Roman Gushchin
9e05e5c7ee signal: restore the override_rlimit logic
Prior to commit d646969055 ("Reimplement RLIMIT_SIGPENDING on top of
ucounts") UCOUNT_RLIMIT_SIGPENDING rlimit was not enforced for a class of
signals.  However now it's enforced unconditionally, even if
override_rlimit is set.  This behavior change caused production issues.  

For example, if the limit is reached and a process receives a SIGSEGV
signal, sigqueue_alloc fails to allocate the necessary resources for the
signal delivery, preventing the signal from being delivered with siginfo. 
This prevents the process from correctly identifying the fault address and
handling the error.  From the user-space perspective, applications are
unaware that the limit has been reached and that the siginfo is
effectively 'corrupted'.  This can lead to unpredictable behavior and
crashes, as we observed with java applications.

Fix this by passing override_rlimit into inc_rlimit_get_ucounts() and skip
the comparison to max there if override_rlimit is set.  This effectively
restores the old behavior.

Link: https://lkml.kernel.org/r/20241104195419.3962584-1-roman.gushchin@linux.dev
Fixes: d646969055 ("Reimplement RLIMIT_SIGPENDING on top of ucounts")
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Co-developed-by: Andrei Vagin <avagin@google.com>
Signed-off-by: Andrei Vagin <avagin@google.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Alexey Gladkov <legion@kernel.org>
Cc: Kees Cook <kees@kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-07 14:14:59 -08:00
Andrei Vagin
432dc0654c ucounts: fix counter leak in inc_rlimit_get_ucounts()
The inc_rlimit_get_ucounts() increments the specified rlimit counter and
then checks its limit.  If the value exceeds the limit, the function
returns an error without decrementing the counter.

Link: https://lkml.kernel.org/r/20241101191940.3211128-1-roman.gushchin@linux.dev
Fixes: 15bc01effe ("ucounts: Fix signal ucount refcounting")
Signed-off-by: Andrei Vagin <avagin@google.com>
Co-developed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Tested-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Alexey Gladkov <legion@kernel.org>
Cc: Kees Cook <kees@kernel.org>
Cc: Andrei Vagin <avagin@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Gladkov <legion@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-07 14:14:59 -08:00
Linus Torvalds
7758b20611 Merge tag 'tracefs-v6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracefs fixes from Steven Rostedt:
 "Fix tracefs mount options.

  Commit 78ff640819 ("vfs: Convert tracefs to use the new mount API")
  broke the gid setting when set by fstab or other mount utility. It is
  ignored when it is set. Fix the code so that it recognises the option
  again and will honor the settings on mount at boot up.

  Update the internal documentation and create a selftest to make sure
  it doesn't break again in the future"

* tag 'tracefs-v6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/selftests: Add tracefs mount options test
  tracing: Document tracefs gid mount option
  tracing: Fix tracefs mount options
2024-11-06 08:08:39 -10:00
Tejun Heo
f7d1b585e1 sched_ext: Add a missing newline at the end of an error message
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-11-05 11:45:24 -10:00
Linus Torvalds
b019b4a670 Merge tag 'timers-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Thomas Gleixner:
 "A single fix for posix CPU timers.

  When a thread is cloned, the posix CPU timers are not inherited.

  If the parent has a CPU timer armed the corresponding tick dependency
  in the tasks tick_dep_mask is set and copied to the new thread, which
  means the new thread and all decendants will prevent the system to go
  into full NOHZ operation.

  Clear the tick dependency mask in copy_process() to fix this"

* tag 'timers-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  posix-cpu-timers: Clear TICK_DEP_BIT_POSIX_TIMER on clone
2024-11-03 08:22:21 -10:00
Linus Torvalds
33e83ffe4c Merge tag 'sched-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Thomas Gleixner:

 - Plug a race between pick_next_task_fair() and try_to_wake_up() where
   both try to write to the same task, even though both paths hold a
   runqueue lock, but obviously from different runqueues.

   The problem is that the store to task::on_rq in __block_task() is
   visible to try_to_wake_up() which assumes that the task is not
   queued. Both sides then operate on the same task.

   Cure it by rearranging __block_task() so the the store to task::on_rq
   is the last operation on the task.

 - Prevent a potential NULL pointer dereference in task_numa_work()

   task_numa_work() iterates the VMAs of a process. A concurrent unmap
   of the address space can result in a NULL pointer return from
   vma_next() which is unchecked.

   Add the missing NULL pointer check to prevent this.

 - Operate on the correct scheduler policy in task_should_scx()

   task_should_scx() returns true when a task should be handled by sched
   EXT. It checks the tasks scheduling policy.

   This fails when the check is done before a policy has been set.

   Cure it by handing the policy into task_should_scx() so it operates
   on the requested value.

 - Add the missing handling of sched EXT in the delayed dequeue
   mechanism. This was simply forgotten.

* tag 'sched-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/ext: Fix scx vs sched_delayed
  sched: Pass correct scheduling policy to __setscheduler_class
  sched/numa: Fix the potential null pointer dereference in task_numa_work()
  sched: Fix pick_next_task_fair() vs try_to_wake_up() race
2024-11-03 08:18:28 -10:00
Linus Torvalds
68f05b251b Merge tag 'perf-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fix from Thomas Gleixner:
 "perf_event_clear_cpumask() uses list_for_each_entry_rcu() without
  being in a RCU read side critical section, which triggers a
  'suspicious RCU usage' warning.

  It turns out that the list walk does not be RCU protected because the
  write side lock is held in this context.

  Change it to a regular list walk"

* tag 'perf-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Fix missing RCU reader protection in perf_event_clear_cpumask()
2024-11-03 08:13:52 -10:00
Linus Torvalds
8f0b844adc Merge tag 'irq-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:

 - Fix an off-by-one error in the failure path of msi_domain_alloc(),
   which causes the cleanup loop to terminate early and leaking the
   first allocated interrupt.

 - Handle a corner case in GIC-V4 versus a lazily mapped Virtual
   Processing Element (VPE). If the VPE has not been mapped because the
   guest has not yet emitted a mapping command, then the set_affinity()
   callback returns an error code, which causes the vCPU management to
   fail.

   Return success in this case without touching the hardware. This will
   be done later when the guest issues the mapping command.

* tag 'irq-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gic-v4: Correctly deal with set_affinity on lazily-mapped VPEs
  genirq/msi: Fix off-by-one error in msi_domain_alloc()
2024-11-03 08:09:25 -10:00
Kalesh Singh
fa17cb4b3b tracing: Document tracefs gid mount option
Commit ee7f366699 ("tracefs: Have new files inherit the ownership of
their parent") and commit 48b27b6b51 ("tracefs: Set all files to the
same group ownership as the mount option") introduced a new gid mount
option that allows specifying a group to apply to all entries in tracefs.

Document this in the tracing readme.

Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Ali Zahraee <ahzahraee@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/20241030171928.4168869-3-kaleshsingh@google.com
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-01 08:57:17 -04:00
Linus Torvalds
5635f18942 Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Pull bpf fixes from Daniel Borkmann:

 - Fix BPF verifier to force a checkpoint when the program's jump
   history becomes too long (Eduard Zingerman)

 - Add several fixes to the BPF bits iterator addressing issues like
   memory leaks and overflow problems (Hou Tao)

 - Fix an out-of-bounds write in trie_get_next_key (Byeonguk Jeong)

 - Fix BPF test infra's LIVE_FRAME frame update after a page has been
   recycled (Toke Høiland-Jørgensen)

 - Fix BPF verifier and undo the 40-bytes extra stack space for
   bpf_fastcall patterns due to various bugs (Eduard Zingerman)

 - Fix a BPF sockmap race condition which could trigger a NULL pointer
   dereference in sock_map_link_update_prog (Cong Wang)

 - Fix tcp_bpf_recvmsg_parser to retrieve seq_copied from tcp_sk under
   the socket lock (Jiayuan Chen)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf, test_run: Fix LIVE_FRAME frame update after a page has been recycled
  selftests/bpf: Add three test cases for bits_iter
  bpf: Use __u64 to save the bits in bits iterator
  bpf: Check the validity of nr_words in bpf_iter_bits_new()
  bpf: Add bpf_mem_alloc_check_size() helper
  bpf: Free dynamically allocated bits in bpf_iter_bits_destroy()
  bpf: disallow 40-bytes extra stack for bpf_fastcall patterns
  selftests/bpf: Add test for trie_get_next_key()
  bpf: Fix out-of-bounds write in trie_get_next_key()
  selftests/bpf: Test with a very short loop
  bpf: Force checkpoint when jmp history is too long
  bpf: fix filed access without lock
  sock_map: fix a NULL pointer dereference in sock_map_link_update_prog()
2024-10-31 14:56:19 -10:00
Peter Zijlstra
69d5e722be sched/ext: Fix scx vs sched_delayed
Commit 98442f0ccd ("sched: Fix delayed_dequeue vs
switched_from_fair()") forgot about scx :/

Fixes: 98442f0ccd ("sched: Fix delayed_dequeue vs switched_from_fair()")
Reported-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lkml.kernel.org/r/20241030104934.GK14555@noisy.programming.kicks-ass.net
2024-10-30 22:42:12 +01:00
Hou Tao
e133938367 bpf: Use __u64 to save the bits in bits iterator
On 32-bit hosts (e.g., arm32), when a bpf program passes a u64 to
bpf_iter_bits_new(), bpf_iter_bits_new() will use bits_copy to store the
content of the u64. However, bits_copy is only 4 bytes, leading to stack
corruption.

The straightforward solution would be to replace u64 with unsigned long
in bpf_iter_bits_new(). However, this introduces confusion and problems
for 32-bit hosts because the size of ulong in bpf program is 8 bytes,
but it is treated as 4-bytes after passed to bpf_iter_bits_new().

Fix it by changing the type of both bits and bit_count from unsigned
long to u64. However, the change is not enough. The main reason is that
bpf_iter_bits_next() uses find_next_bit() to find the next bit and the
pointer passed to find_next_bit() is an unsigned long pointer instead
of a u64 pointer. For 32-bit little-endian host, it is fine but it is
not the case for 32-bit big-endian host. Because under 32-bit big-endian
host, the first iterated unsigned long will be the bits 32-63 of the u64
instead of the expected bits 0-31. Therefore, in addition to changing
the type, swap the two unsigned longs within the u64 for 32-bit
big-endian host.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20241030100516.3633640-5-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-30 12:13:46 -07:00
Hou Tao
393397fbdc bpf: Check the validity of nr_words in bpf_iter_bits_new()
Check the validity of nr_words in bpf_iter_bits_new(). Without this
check, when multiplication overflow occurs for nr_bits (e.g., when
nr_words = 0x0400-0001, nr_bits becomes 64), stack corruption may occur
due to bpf_probe_read_kernel_common(..., nr_bytes = 0x2000-0008).

Fix it by limiting the maximum value of nr_words to 511. The value is
derived from the current implementation of BPF memory allocator. To
ensure compatibility if the BPF memory allocator's size limitation
changes in the future, use the helper bpf_mem_alloc_check_size() to
check whether nr_bytes is too larger. And return -E2BIG instead of
-ENOMEM for oversized nr_bytes.

Fixes: 4665415975 ("bpf: Add bits iterator")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20241030100516.3633640-4-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-30 12:13:46 -07:00
Hou Tao
62a898b07b bpf: Add bpf_mem_alloc_check_size() helper
Introduce bpf_mem_alloc_check_size() to check whether the allocation
size exceeds the limitation for the kmalloc-equivalent allocator. The
upper limit for percpu allocation is LLIST_NODE_SZ bytes larger than
non-percpu allocation, so a percpu argument is added to the helper.

The helper will be used in the following patch to check whether the size
parameter passed to bpf_mem_alloc() is too big.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20241030100516.3633640-3-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-30 12:13:46 -07:00
Hou Tao
101ccfbabf bpf: Free dynamically allocated bits in bpf_iter_bits_destroy()
bpf_iter_bits_destroy() uses "kit->nr_bits <= 64" to check whether the
bits are dynamically allocated. However, the check is incorrect and may
cause a kmemleak as shown below:

unreferenced object 0xffff88812628c8c0 (size 32):
  comm "swapper/0", pid 1, jiffies 4294727320
  hex dump (first 32 bytes):
	b0 c1 55 f5 81 88 ff ff f0 f0 f0 f0 f0 f0 f0 f0  ..U...........
	f0 f0 f0 f0 f0 f0 f0 f0 00 00 00 00 00 00 00 00  ..............
  backtrace (crc 781e32cc):
	[<00000000c452b4ab>] kmemleak_alloc+0x4b/0x80
	[<0000000004e09f80>] __kmalloc_node_noprof+0x480/0x5c0
	[<00000000597124d6>] __alloc.isra.0+0x89/0xb0
	[<000000004ebfffcd>] alloc_bulk+0x2af/0x720
	[<00000000d9c10145>] prefill_mem_cache+0x7f/0xb0
	[<00000000ff9738ff>] bpf_mem_alloc_init+0x3e2/0x610
	[<000000008b616eac>] bpf_global_ma_init+0x19/0x30
	[<00000000fc473efc>] do_one_initcall+0xd3/0x3c0
	[<00000000ec81498c>] kernel_init_freeable+0x66a/0x940
	[<00000000b119f72f>] kernel_init+0x20/0x160
	[<00000000f11ac9a7>] ret_from_fork+0x3c/0x70
	[<0000000004671da4>] ret_from_fork_asm+0x1a/0x30

That is because nr_bits will be set as zero in bpf_iter_bits_next()
after all bits have been iterated.

Fix the issue by setting kit->bit to kit->nr_bits instead of setting
kit->nr_bits to zero when the iteration completes in
bpf_iter_bits_next(). In addition, use "!nr_bits || bits >= nr_bits" to
check whether the iteration is complete and still use "nr_bits > 64" to
indicate whether bits are dynamically allocated. The "!nr_bits" check is
necessary because bpf_iter_bits_new() may fail before setting
kit->nr_bits, and this condition will stop the iteration early instead
of accessing the zeroed or freed kit->bits.

Considering the initial value of kit->bits is -1 and the type of
kit->nr_bits is unsigned int, change the type of kit->nr_bits to int.
The potential overflow problem will be handled in the following patch.

Fixes: 4665415975 ("bpf: Add bits iterator")
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20241030100516.3633640-2-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-30 12:13:46 -07:00