WSL2-Linux-Kernel/kernel
Andrii Nakryiko 138c67677f bpf: Fix use-after-free of bpf_link when priming half-fails
If bpf_link_prime() succeeds to allocate new anon file, but then fails to
allocate ID for it, link priming is considered to be failed and user is
supposed ot be able to directly kfree() bpf_link, because it was never exposed
to user-space.

But at that point file already keeps a pointer to bpf_link and will eventually
call bpf_link_release(), so if bpf_link was kfree()'d by caller, that would
lead to use-after-free.

Fix this by first allocating ID and only then allocating file. Adding ID to
link_idr is ok, because link at that point still doesn't have its ID set, so
no user-space process can create a new FD for it.

Fixes: a3b80e1078 ("bpf: Allocate ID for bpf_link")
Reported-by: syzbot+39b64425f91b5aab714d@syzkaller.appspotmail.com
Suggested-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200501185622.3088964-1-andriin@fb.com
2020-05-01 15:13:05 -07:00
..
bpf bpf: Fix use-after-free of bpf_link when priming half-fails 2020-05-01 15:13:05 -07:00
cgroup bpf: Refactor bpf_link update handling 2020-04-28 17:27:07 -07:00
configs compiler: remove CONFIG_OPTIMIZE_INLINING entirely 2020-04-07 10:43:42 -07:00
debug SPDX patches for 5.7-rc1. 2020-04-03 13:12:26 -07:00
dma dma-debug: fix displaying of dma allocation type 2020-04-08 21:46:57 +02:00
events Merge branch 'work.sysctl' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-04-28 21:23:38 +02:00
gcov kernel/gcov/fs.c: gcov_seq_next() should increase position index 2020-04-10 15:36:22 -07:00
irq genirq: Remove setup_irq() and remove_irq() 2020-04-14 10:08:50 +02:00
livepatch
locking locking/lockdep: Improve 'invalid wait context' splat 2020-04-08 12:05:07 +02:00
power PM / sleep: handle the compat case in snapshot_set_swap_area() 2020-04-06 21:42:36 +02:00
printk sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
rcu Merge branch 'urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/urgent 2020-04-14 08:36:41 +02:00
sched Merge branch 'work.sysctl' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-04-28 21:23:38 +02:00
time Merge branch 'work.sysctl' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-04-28 21:23:38 +02:00
trace Merge branch 'work.sysctl' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-04-28 21:23:38 +02:00
.gitignore
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
Makefile
acct.c
async.c
audit.c audit: check the length of userspace generated audit records 2020-04-20 17:10:58 -04:00
audit.h
audit_fsnotify.c
audit_tree.c
audit_watch.c \n 2020-04-06 08:58:42 -07:00
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c
compat.c
configs.c
context_tracking.c
cpu.c CPU (hotplug) updates: 2020-03-30 18:06:39 -07:00
cpu_pm.c
crash_core.c
crash_dump.c
cred.c
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c proc: Put thread_pid in release_task not proc_flush_pid 2020-04-24 15:49:00 -05:00
extable.c kernel/extable.c: use address-of operator on section symbols 2020-04-07 10:43:42 -07:00
fail_function.c
fork.c clone3: add build-time CLONE_ARGS_SIZE_VER* validity checks 2020-04-15 09:56:32 +02:00
freezer.c
futex.c
gen_kheaders.sh
groups.c
hung_task.c
iomem.c
irq_work.c
jump_label.c
kallsyms.c kallsyms: unexport kallsyms_lookup_name() and kallsyms_on_each_symbol() 2020-04-07 10:43:44 -07:00
kcmp.c
kcov.c
kexec.c
kexec_core.c
kexec_elf.c
kexec_file.c
kexec_internal.h
kheaders.c
kmod.c kmod: make request_module() return an error when autoloading is disabled 2020-04-10 15:36:22 -07:00
kprobes.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
ksysfs.c
kthread.c
latencytop.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
module-internal.h
module.c kernel/module: Hide vermagic header file from general use 2020-04-21 13:27:37 -07:00
module_signature.c
module_signing.c
notifier.c
nsproxy.c
padata.c
panic.c
params.c
pid.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-04-10 12:59:56 -07:00
pid_namespace.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
profile.c
ptrace.c
range.c
reboot.c
relay.c
resource.c
rseq.c
seccomp.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
signal.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-04-23 13:30:18 -07:00
smp.c
smpboot.c
smpboot.h
softirq.c
stackleak.c
stacktrace.c
stop_machine.c
sys.c
sys_ni.c
sysctl-test.c
sysctl.c bpf: Sharing bpf runtime stats with BPF_ENABLE_STATS 2020-05-01 10:36:32 -07:00
sysctl_binary.c
task_work.c
taskstats.c
test_kprobes.c
torture.c CPU (hotplug) updates: 2020-03-30 18:06:39 -07:00
tracepoint.c
tsacct.c
ucount.c ucount: Make sure ucounts in /proc/sys/user don't regress again 2020-04-07 21:51:27 +02:00
uid16.c
uid16.h
umh.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
up.c
user-return-notifier.c
user.c
user_namespace.c
utsname.c
utsname_sysctl.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
watchdog.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
watchdog_hld.c
workqueue.c workqueue: Remove the warning in wq_worker_sleeping() 2020-04-08 11:35:20 +02:00
workqueue_internal.h