Andrii Nakryiko f44ec8733a bpf: put bpf_link's program when link is safe to be deallocated ... In general, BPF link's underlying BPF program should be considered to be reachable through attach hook -> link -> prog chain, and, pessimistically, we have to assume that as long as link's memory is not safe to free, attach hook's code might hold a pointer to BPF program and use it. As such, it's not (generally) correct to put link's program early before waiting for RCU GPs to go through. More eager bpf_prog_put() that we currently do is mostly correct due to BPF program's release code doing similar RCU GP waiting, but as will be shown in the following patches, BPF program can be non-sleepable (and, thus, reliant on only "classic" RCU GP), while BPF link's attach hook can have sleepable semantics and needs to be protected by RCU Tasks Trace, and for such cases BPF link has to go through RCU Tasks Trace + "classic" RCU GPs before being deallocated. And so, if we put BPF program early, we might free BPF program before we free BPF link, leading to use-after-free situation. So, this patch defers bpf_prog_put() until we are ready to perform bpf_link's deallocation. At worst, this delays BPF program freeing by one extra RCU GP, but that seems completely acceptable. Alternatively, we'd need more elaborate ways to determine BPF hook, BPF link, and BPF program lifetimes, and how they relate to each other, which seems like an unnecessary complication. Note, for most BPF links we still will perform eager bpf_prog_put() and link dealloc, so for those BPF links there are no observable changes whatsoever. Only BPF links that use deferred dealloc might notice slightly delayed freeing of BPF programs. Also, to reduce code and logic duplication, extract program put + link dealloc logic into bpf_link_dealloc() helper. Link: https://lore.kernel.org/20241101181754.782341-1-andrii@kernel.org Tested-by: Jordan Rife <jrife@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>		2024-11-01 14:39:06 -04:00
..
bpf	bpf: put bpf_link's program when link is safe to be deallocated	2024-11-01 14:39:06 -04:00
cgroup	struct fd layout change (and conversion to accessor helpers)	2024-09-23 09:35:36 -07:00
configs	tinyconfig: remove unnecessary 'is not set' for choice blocks	2024-09-01 20:34:38 +09:00
debug	move asm/unaligned.h to linux/unaligned.h	2024-10-02 17:23:23 -04:00
dma	dma-mapping: report unlimited DMA addressing in IOMMU DMA path	2024-09-23 08:38:56 +02:00
entry	treewide: context_tracking: Rename CONTEXT_* into CT_STATE_*	2024-07-29 07:33:10 +05:30
events	uprobes: fix kernel info leak via "[uprobes]" vma	2024-09-30 08:19:11 +09:00
futex	fault-inject: improve build for CONFIG_FAULT_INJECTION=n	2024-09-01 20:43:33 -07:00
gcov	gcov: add support for GCC 14	2024-06-15 10:43:06 -07:00
irq	pci-v6.12-changes	2024-09-23 12:47:06 -07:00
kcsan	kcsan: Use min() to fix Coccinelle warning	2024-08-01 16:40:44 -07:00
livepatch	livepatch: Replace snprintf() with sysfs_emit()	2024-07-02 16:56:18 +02:00
locking	Locking changes for v6.12:	2024-09-29 08:51:30 -07:00
module	Modules changes for v6.12-rc1	2024-09-28 09:06:15 -07:00
power	[tree-wide] finally take no_llseek out	2024-09-27 08:18:43 -07:00
printk	drm next for 6.12-rc1	2024-09-19 10:18:15 +02:00
rcu	rcu/kvfree: Refactor kvfree_rcu_queue_batch()	2024-10-01 18:30:42 +02:00
sched	sched: psi: fix bogus pressure spikes from aggregation race	2024-10-03 16:03:16 -07:00
time	[tree-wide] finally take no_llseek out	2024-09-27 08:18:43 -07:00
trace	tracing: Replace strncpy() with strscpy() when copying comm	2024-11-01 14:37:31 -04:00
.gitignore
acct.c	kernel misc: Remove the now superfluous sentinel elements from ctl_table array	2024-04-24 09:43:53 +02:00
async.c
audit.c	audit: Make use of str_enabled_disabled() helper	2024-09-03 16:35:16 -04:00
audit.h
audit_fsnotify.c
audit_tree.c	fsnotify: create a wrapper fsnotify_find_inode_mark()	2024-04-04 16:24:16 +02:00
audit_watch.c	fsnotify: create a wrapper fsnotify_find_inode_mark()	2024-04-04 16:24:16 +02:00
auditfilter.c	audit: use task_tgid_nr() instead of task_pid_nr()	2024-08-28 16:48:28 -04:00
auditsc.c	audit: use task_tgid_nr() instead of task_pid_nr()	2024-08-28 16:48:28 -04:00
backtracetest.c	backtracetest: add MODULE_DESCRIPTION()	2024-06-24 22:24:55 -07:00
bounds.c	bounds: Use the right number of bits for power-of-two CONFIG_NR_CPUS	2024-04-29 08:29:29 -07:00
capability.c
cfi.c
compat.c
configs.c
context_tracking.c	context_tracking, rcu: Rename rcu_dyntick trace event into rcu_watching	2024-08-15 21:30:43 +05:30
cpu.c	Updates for timers and timekeeping:	2024-09-17 07:25:37 +02:00
cpu_pm.c
crash_core.c	Document/kexec: generalize crash hotplug description	2024-09-01 20:43:37 -07:00
crash_reserve.c	crash: fix crash memory reserve exceed system memory bug	2024-09-01 20:43:30 -07:00
cred.c
delayacct.c	sysctl: treewide: constify the ctl_table argument of proc_handlers	2024-07-24 20:59:29 +02:00
dma.c
elfcorehdr.c
exec_domain.c
exit.c	ALong with the usual shower of singleton patches, notable patch series in	2024-09-21 07:29:05 -07:00
exit.h
extable.c
fail_function.c
fork.c	close_range(): fix the logics in descriptor table trimming	2024-09-29 21:52:29 -04:00
freezer.c	sched,freezer: Mark TASK_FROZEN special	2024-08-17 11:06:44 +02:00
gen_kheaders.sh	kheaders: use command -v to test for existence of cpio	2024-05-30 01:13:20 +09:00
groups.c
hung_task.c	sysctl: treewide: constify the ctl_table argument of proc_handlers	2024-07-24 20:59:29 +02:00
iomem.c
irq_work.c
jump_label.c	jump_label: Fix static_key_slow_dec() yet again	2024-09-10 11:57:27 +02:00
kallsyms.c	kallsyms: Match symbols exactly with CONFIG_LTO_CLANG	2024-08-15 09:33:35 -07:00
kallsyms_internal.h	kallsyms: get rid of code for absolute kallsyms	2024-07-20 16:33:21 +09:00
kallsyms_selftest.c	kallsyms: Match symbols exactly with CONFIG_LTO_CLANG	2024-08-15 09:33:35 -07:00
kallsyms_selftest.h
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.kexec
Kconfig.locks
Kconfig.preempt	sched_ext: Build fix on !CONFIG_STACKTRACE[_SUPPORT]	2024-08-01 07:08:01 -10:00
kcov.c	Updates for KCOV instrumentation on x86:	2024-09-17 12:40:34 +02:00
kexec.c	crash: add a new kexec flag for hotplug support	2024-04-23 14:59:01 +10:00
kexec_core.c	sysctl: treewide: constify the ctl_table argument of proc_handlers	2024-07-24 20:59:29 +02:00
kexec_elf.c
kexec_file.c	kexec_file: fix elfcorehdr digest exclusion when CONFIG_CRASH_HOTPLUG=y	2024-09-01 17:59:01 -07:00
kexec_internal.h	kexec: use atomic_try_cmpxchg_acquire() in kexec_trylock()	2024-09-01 20:43:23 -07:00
kheaders.c
kprobes.c	kprobes: Fix to check symbol prefixes correctly	2024-08-05 14:04:03 +09:00
ksyms_common.c
ksysfs.c	profiling: remove prof_cpu_mask	2024-07-29 10:45:54 -07:00
kthread.c	kthread: Fix task state in kthread worker if being frozen	2024-09-10 09:51:14 +02:00
latencytop.c	sysctl: treewide: constify the ctl_table argument of proc_handlers	2024-07-24 20:59:29 +02:00
Makefile	mm: move kernel/numa.c to mm/	2024-09-03 21:15:26 -07:00
module_signature.c
notifier.c
nsproxy.c	introduce fd_file(), convert all accessors to it.	2024-08-12 22:00:43 -04:00
padata.c	This update includes the following changes:	2024-09-16 06:28:28 +02:00
panic.c	drm next for 6.12-rc1	2024-09-19 10:18:15 +02:00
params.c
pid.c	introduce fd_file(), convert all accessors to it.	2024-08-12 22:00:43 -04:00
pid_namespace.c	sysctl: treewide: constify the ctl_table argument of proc_handlers	2024-07-24 20:59:29 +02:00
pid_sysctl.h	sysctl: treewide: constify the ctl_table argument of proc_handlers	2024-07-24 20:59:29 +02:00
profile.c	profiling: remove profile=sleep support	2024-08-04 13:36:28 -07:00
ptrace.c
range.c
reboot.c	kernel misc: Remove the now superfluous sentinel elements from ctl_table array	2024-04-24 09:43:53 +02:00
regset.c	regset: use kvzalloc() for regset_get_alloc()	2024-04-25 21:07:03 -07:00
relay.c	[tree-wide] finally take no_llseek out	2024-09-27 08:18:43 -07:00
resource.c	ALong with the usual shower of singleton patches, notable patch series in	2024-09-21 07:29:05 -07:00
resource_kunit.c	resource, kunit: add test case for region_intersects()	2024-09-17 01:07:00 -07:00
rseq.c
scftorture.c	scftorture: Make torture_type static	2024-05-30 15:31:51 -07:00
scs.c
seccomp.c	sysctl: treewide: constify the ctl_table argument of proc_handlers	2024-07-24 20:59:29 +02:00
signal.c	Revert "binfmt_elf, coredump: Log the reason of the failed core dumps"	2024-09-26 11:39:02 -07:00
smp.c	smp: print only local CPU info when sched_clock goes backward	2024-08-15 00:06:48 +05:30
smpboot.c
smpboot.h
softirq.c	softirq: Remove unused 'action' parameter from action callback	2024-08-20 17:13:40 +02:00
stackleak.c	sysctl: treewide: constify the ctl_table argument of proc_handlers	2024-07-24 20:59:29 +02:00
stacktrace.c
static_call.c
static_call_inline.c	static_call: Replace pointless WARN_ON() in static_call_module_notify()	2024-09-06 16:29:22 +02:00
stop_machine.c	rcu: Rename rcu_momentary_dyntick_idle() into rcu_momentary_eqs()	2024-08-15 21:30:42 +05:30
sys.c	struct fd layout change (and conversion to accessor helpers)	2024-09-23 09:35:36 -07:00
sys_ni.c	Probes updates for v6.11:	2024-07-18 12:19:20 -07:00
sysctl-test.c	sysctl: Add module description to sysctl-testing	2024-06-03 15:20:37 +02:00
sysctl.c	sysctl: treewide: constify the ctl_table argument of proc_handlers	2024-07-24 20:59:29 +02:00
task_work.c	task_work: make TWA_NMI_CURRENT handling conditional on IRQ_WORK	2024-07-29 12:05:06 -07:00
taskstats.c	introduce fd_file(), convert all accessors to it.	2024-08-12 22:00:43 -04:00
torture.c	torture: Add MODULE_DESCRIPTION()	2024-05-30 15:31:38 -07:00
tracepoint.c	tracing: Fix syscall tracepoint use-after-free	2024-11-01 14:37:31 -04:00
tsacct.c	tsacct: replace strncpy() with strscpy()	2024-07-12 16:39:53 -07:00
ucount.c	sysctl changes for v6.10-rc1	2024-05-17 17:31:24 -07:00
uid16.c
uid16.h
umh.c	sysctl: treewide: constify the ctl_table argument of proc_handlers	2024-07-24 20:59:29 +02:00
up.c
user-return-notifier.c
user.c	uidgid: make sure we fit into one cacheline	2024-09-12 12:16:09 +02:00
user_namespace.c	user_namespace: use kmemdup_array() instead of kmemdup() for multiple allocation	2024-09-09 16:47:42 -07:00
usermode_driver.c
utsname.c
utsname_sysctl.c	sysctl: treewide: constify the ctl_table argument of proc_handlers	2024-07-24 20:59:29 +02:00
vhost_task.c	vhost_task: Handle SIGKILL by flushing work and exiting	2024-05-22 08:31:15 -04:00
vmcore_info.c	mm: support only one page_type per page	2024-09-03 21:15:43 -07:00
watch_queue.c	introduce fd_file(), convert all accessors to it.	2024-08-12 22:00:43 -04:00
watchdog.c	watchdog: handle the ENODEV failure case of lockup_detector_delay_init() separately	2024-09-01 20:43:32 -07:00
watchdog_buddy.c
watchdog_perf.c	watchdog/perf: properly initialize the turbo mode timestamp and rearm counter	2024-07-17 21:11:34 -07:00
workqueue.c	workqueue: Changes for v6.12	2024-09-18 06:59:44 +02:00
workqueue_internal.h