linux-stable.git/kernel/bpf/syscall.c, branch v6.1.44 Linux kernel stable tree bpf: Print a warning only if writing to unprivileged_bpf_disabled. 2023-07-27T06:50:34+00:00 Kui-Feng Lee thinker.li@gmail.com 2023-05-02T18:14:18+00:00 10fa03a9c1bcdbd20f8f538542a3d902f9f22f3c [ Upstream commit fedf99200ab086c42a572fca1d7266b06cdc3e3f ] Only print the warning message if you are writing to "/proc/sys/kernel/unprivileged_bpf_disabled". The kernel may print an annoying warning when you read "/proc/sys/kernel/unprivileged_bpf_disabled" saying WARNING: Unprivileged eBPF is enabled with eIBRS on, data leaks possible via Spectre v2 BHB attacks! However, this message is only meaningful when the feature is disabled or enabled. Signed-off-by: Kui-Feng Lee <kuifeng@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20230502181418.308479-1-kuifeng@meta.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit fedf99200ab086c42a572fca1d7266b06cdc3e3f ]

Only print the warning message if you are writing to
"/proc/sys/kernel/unprivileged_bpf_disabled".

The kernel may print an annoying warning when you read
"/proc/sys/kernel/unprivileged_bpf_disabled" saying

  WARNING: Unprivileged eBPF is enabled with eIBRS on, data leaks possible
  via Spectre v2 BHB attacks!

However, this message is only meaningful when the feature is
disabled or enabled.

Signed-off-by: Kui-Feng Lee <kuifeng@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20230502181418.308479-1-kuifeng@meta.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf: Force kprobe multi expected_attach_type for kprobe_multi link 2023-06-28T09:12:33+00:00 Jiri Olsa jolsa@kernel.org 2023-06-18T13:14:14+00:00 1b7b048c228effa3c66ac183811e394fa4d9a28a [ Upstream commit db8eae6bc5c702d8e3ab2d0c6bb5976c131576eb ] We currently allow to create perf link for program with expected_attach_type == BPF_TRACE_KPROBE_MULTI. This will cause crash when we call helpers like get_attach_cookie or get_func_ip in such program, because it will call the kprobe_multi's version (current->bpf_ctx context setup) of those helpers while it expects perf_link's current->bpf_ctx context setup. Making sure that we use BPF_TRACE_KPROBE_MULTI expected_attach_type only for programs attaching through kprobe_multi link. Fixes: ca74823c6e16 ("bpf: Add cookie support to programs attached with kprobe multi link") Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230618131414.75649-1-jolsa@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit db8eae6bc5c702d8e3ab2d0c6bb5976c131576eb ]

We currently allow to create perf link for program with
expected_attach_type == BPF_TRACE_KPROBE_MULTI.

This will cause crash when we call helpers like get_attach_cookie or
get_func_ip in such program, because it will call the kprobe_multi's
version (current->bpf_ctx context setup) of those helpers while it
expects perf_link's current->bpf_ctx context setup.

Making sure that we use BPF_TRACE_KPROBE_MULTI expected_attach_type
only for programs attaching through kprobe_multi link.

Fixes: ca74823c6e16 ("bpf: Add cookie support to programs attached with kprobe multi link")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230618131414.75649-1-jolsa@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf: restore the ebpf program ID for BPF_AUDIT_UNLOAD and PERF_BPF_EVENT_PROG_UNLOAD 2023-01-24T06:24:37+00:00 Paul Moore paul@paul-moore.com 2023-01-06T15:43:59+00:00 8de08b0c44ae7bb1500893c5edbf093d72cbd3b8 commit ef01f4e25c1760920e2c94f1c232350277ace69b upstream. When changing the ebpf program put() routines to support being called from within IRQ context the program ID was reset to zero prior to calling the perf event and audit UNLOAD record generators, which resulted in problems as the ebpf program ID was bogus (always zero). This patch addresses this problem by removing an unnecessary call to bpf_prog_free_id() in __bpf_prog_offload_destroy() and adjusting __bpf_prog_put() to only call bpf_prog_free_id() after audit and perf have finished their bpf program unload tasks in bpf_prog_put_deferred(). For the record, no one can determine, or remember, why it was necessary to free the program ID, and remove it from the IDR, prior to executing bpf_prog_put_deferred(); regardless, both Stanislav and Alexei agree that the approach in this patch should be safe. It is worth noting that when moving the bpf_prog_free_id() call, the do_idr_lock parameter was forced to true as the ebpf devs determined this was the correct as the do_idr_lock should always be true. The do_idr_lock parameter will be removed in a follow-up patch, but it was kept here to keep the patch small in an effort to ease any stable backports. I also modified the bpf_audit_prog() logic used to associate the AUDIT_BPF record with other associated records, e.g. @ctx != NULL. Instead of keying off the operation, it now keys off the execution context, e.g. '!in_irg && !irqs_disabled()', which is much more appropriate and should help better connect the UNLOAD operations with the associated audit state (other audit records). Cc: stable@vger.kernel.org Fixes: d809e134be7a ("bpf: Prepare bpf_prog_put() to be called from irq context.") Reported-by: Burn Alting <burn.alting@iinet.net.au> Reported-by: Jiri Olsa <olsajiri@gmail.com> Suggested-by: Stanislav Fomichev <sdf@google.com> Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20230106154400.74211-1-paul@paul-moore.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit ef01f4e25c1760920e2c94f1c232350277ace69b upstream.

When changing the ebpf program put() routines to support being called
from within IRQ context the program ID was reset to zero prior to
calling the perf event and audit UNLOAD record generators, which
resulted in problems as the ebpf program ID was bogus (always zero).
This patch addresses this problem by removing an unnecessary call to
bpf_prog_free_id() in __bpf_prog_offload_destroy() and adjusting
__bpf_prog_put() to only call bpf_prog_free_id() after audit and perf
have finished their bpf program unload tasks in
bpf_prog_put_deferred().  For the record, no one can determine, or
remember, why it was necessary to free the program ID, and remove it
from the IDR, prior to executing bpf_prog_put_deferred();
regardless, both Stanislav and Alexei agree that the approach in this
patch should be safe.

It is worth noting that when moving the bpf_prog_free_id() call, the
do_idr_lock parameter was forced to true as the ebpf devs determined
this was the correct as the do_idr_lock should always be true.  The
do_idr_lock parameter will be removed in a follow-up patch, but it
was kept here to keep the patch small in an effort to ease any stable
backports.

I also modified the bpf_audit_prog() logic used to associate the
AUDIT_BPF record with other associated records, e.g. @ctx != NULL.
Instead of keying off the operation, it now keys off the execution
context, e.g. '!in_irg && !irqs_disabled()', which is much more
appropriate and should help better connect the UNLOAD operations with
the associated audit state (other audit records).

Cc: stable@vger.kernel.org
Fixes: d809e134be7a ("bpf: Prepare bpf_prog_put() to be called from irq context.")
Reported-by: Burn Alting <burn.alting@iinet.net.au>
Reported-by: Jiri Olsa <olsajiri@gmail.com>
Suggested-by: Stanislav Fomichev <sdf@google.com>
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230106154400.74211-1-paul@paul-moore.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bpf: prevent leak of lsm program after failed attach 2022-12-31T12:32:54+00:00 Milan Landaverde milan@mdaverde.com 2022-12-13T17:57:14+00:00 6a1504dd36cd9a0a69250d61da8bdb17b29f1fe8 [ Upstream commit e89f3edffb860a0f54a9ed16deadb7a4a1fa3862 ] In [0], we added the ability to bpf_prog_attach LSM programs to cgroups, but in our validation to make sure the prog is meant to be attached to BPF_LSM_CGROUP, we return too early if the check fails. This results in lack of decrementing prog's refcnt (through bpf_prog_put) leaving the LSM program alive past the point of the expected lifecycle. This fix allows for the decrement to take place. [0] https://lore.kernel.org/all/20220628174314.1216643-4-sdf@google.com/ Fixes: 69fd337a975c ("bpf: per-cgroup lsm flavor") Signed-off-by: Milan Landaverde <milan@mdaverde.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20221213175714.31963-1-milan@mdaverde.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e89f3edffb860a0f54a9ed16deadb7a4a1fa3862 ]

In [0], we added the ability to bpf_prog_attach LSM programs to cgroups,
but in our validation to make sure the prog is meant to be attached to
BPF_LSM_CGROUP, we return too early if the check fails. This results in
lack of decrementing prog's refcnt (through bpf_prog_put)
leaving the LSM program alive past the point of the expected lifecycle.
This fix allows for the decrement to take place.

[0] https://lore.kernel.org/all/20220628174314.1216643-4-sdf@google.com/

Fixes: 69fd337a975c ("bpf: per-cgroup lsm flavor")
Signed-off-by: Milan Landaverde <milan@mdaverde.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20221213175714.31963-1-milan@mdaverde.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-10-04T00:44:18+00:00 Jakub Kicinski kuba@kernel.org 2022-10-04T00:44:18+00:00 e52f7c1ddf3e47243c330923ea764e7ccfbe99f7 Merge in the left-over fixes before the net-next pull-request. Conflicts: drivers/net/ethernet/mediatek/mtk_ppe.c ae3ed15da588 ("net: ethernet: mtk_eth_soc: fix state in __mtk_foe_entry_clear") 9d8cb4c096ab ("net: ethernet: mtk_eth_soc: add foe_entry_size to mtk_eth_soc") https://lore.kernel.org/all/6cb6893b-4921-a068-4c30-1109795110bb@tessares.net/ kernel/bpf/helpers.c 8addbfc7b308 ("bpf: Gate dynptr API behind CAP_BPF") 5679ff2f138f ("bpf: Move bpf_loop and bpf_for_each_map_elem under CAP_BPF") 8a67f2de9b1d ("bpf: expose bpf_strtol and bpf_strtoul to all program types") https://lore.kernel.org/all/20221003201957.13149-1-daniel@iogearbox.net/ Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Merge in the left-over fixes before the net-next pull-request.

Conflicts:

drivers/net/ethernet/mediatek/mtk_ppe.c
  ae3ed15da588 ("net: ethernet: mtk_eth_soc: fix state in __mtk_foe_entry_clear")
  9d8cb4c096ab ("net: ethernet: mtk_eth_soc: add foe_entry_size to mtk_eth_soc")
https://lore.kernel.org/all/6cb6893b-4921-a068-4c30-1109795110bb@tessares.net/

kernel/bpf/helpers.c
  8addbfc7b308 ("bpf: Gate dynptr API behind CAP_BPF")
  5679ff2f138f ("bpf: Move bpf_loop and bpf_for_each_map_elem under CAP_BPF")
  8a67f2de9b1d ("bpf: expose bpf_strtol and bpf_strtoul to all program types")
https://lore.kernel.org/all/20221003201957.13149-1-daniel@iogearbox.net/

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
bpf: Prevent bpf program recursion for raw tracepoint probes 2022-09-22T01:05:44+00:00 Jiri Olsa jolsa@kernel.org 2022-09-16T07:19:14+00:00 05b24ff9b2cfabfcfd951daaa915a036ab53c9e1 We got report from sysbot [1] about warnings that were caused by bpf program attached to contention_begin raw tracepoint triggering the same tracepoint by using bpf_trace_printk helper that takes trace_printk_lock lock. Call Trace: <TASK> ? trace_event_raw_event_bpf_trace_printk+0x5f/0x90 bpf_trace_printk+0x2b/0xe0 bpf_prog_a9aec6167c091eef_prog+0x1f/0x24 bpf_trace_run2+0x26/0x90 native_queued_spin_lock_slowpath+0x1c6/0x2b0 _raw_spin_lock_irqsave+0x44/0x50 bpf_trace_printk+0x3f/0xe0 bpf_prog_a9aec6167c091eef_prog+0x1f/0x24 bpf_trace_run2+0x26/0x90 native_queued_spin_lock_slowpath+0x1c6/0x2b0 _raw_spin_lock_irqsave+0x44/0x50 bpf_trace_printk+0x3f/0xe0 bpf_prog_a9aec6167c091eef_prog+0x1f/0x24 bpf_trace_run2+0x26/0x90 native_queued_spin_lock_slowpath+0x1c6/0x2b0 _raw_spin_lock_irqsave+0x44/0x50 bpf_trace_printk+0x3f/0xe0 bpf_prog_a9aec6167c091eef_prog+0x1f/0x24 bpf_trace_run2+0x26/0x90 native_queued_spin_lock_slowpath+0x1c6/0x2b0 _raw_spin_lock_irqsave+0x44/0x50 __unfreeze_partials+0x5b/0x160 ... The can be reproduced by attaching bpf program as raw tracepoint on contention_begin tracepoint. The bpf prog calls bpf_trace_printk helper. Then by running perf bench the spin lock code is forced to take slow path and call contention_begin tracepoint. Fixing this by skipping execution of the bpf program if it's already running, Using bpf prog 'active' field, which is being currently used by trampoline programs for the same reason. Moving bpf_prog_inc_misses_counter to syscall.c because trampoline.c is compiled in just for CONFIG_BPF_JIT option. Reviewed-by: Stanislav Fomichev <sdf@google.com> Reported-by: syzbot+2251879aa068ad9c960d@syzkaller.appspotmail.com [1] https://lore.kernel.org/bpf/YxhFe3EwqchC%2FfYf@krava/T/#t Signed-off-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20220916071914.7156-1-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
We got report from sysbot [1] about warnings that were caused by
bpf program attached to contention_begin raw tracepoint triggering
the same tracepoint by using bpf_trace_printk helper that takes
trace_printk_lock lock.

 Call Trace:
  <TASK>
  ? trace_event_raw_event_bpf_trace_printk+0x5f/0x90
  bpf_trace_printk+0x2b/0xe0
  bpf_prog_a9aec6167c091eef_prog+0x1f/0x24
  bpf_trace_run2+0x26/0x90
  native_queued_spin_lock_slowpath+0x1c6/0x2b0
  _raw_spin_lock_irqsave+0x44/0x50
  bpf_trace_printk+0x3f/0xe0
  bpf_prog_a9aec6167c091eef_prog+0x1f/0x24
  bpf_trace_run2+0x26/0x90
  native_queued_spin_lock_slowpath+0x1c6/0x2b0
  _raw_spin_lock_irqsave+0x44/0x50
  bpf_trace_printk+0x3f/0xe0
  bpf_prog_a9aec6167c091eef_prog+0x1f/0x24
  bpf_trace_run2+0x26/0x90
  native_queued_spin_lock_slowpath+0x1c6/0x2b0
  _raw_spin_lock_irqsave+0x44/0x50
  bpf_trace_printk+0x3f/0xe0
  bpf_prog_a9aec6167c091eef_prog+0x1f/0x24
  bpf_trace_run2+0x26/0x90
  native_queued_spin_lock_slowpath+0x1c6/0x2b0
  _raw_spin_lock_irqsave+0x44/0x50
  __unfreeze_partials+0x5b/0x160
  ...

The can be reproduced by attaching bpf program as raw tracepoint on
contention_begin tracepoint. The bpf prog calls bpf_trace_printk
helper. Then by running perf bench the spin lock code is forced to
take slow path and call contention_begin tracepoint.

Fixing this by skipping execution of the bpf program if it's
already running, Using bpf prog 'active' field, which is being
currently used by trampoline programs for the same reason.

Moving bpf_prog_inc_misses_counter to syscall.c because
trampoline.c is compiled in just for CONFIG_BPF_JIT option.

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Reported-by: syzbot+2251879aa068ad9c960d@syzkaller.appspotmail.com
[1] https://lore.kernel.org/bpf/YxhFe3EwqchC%2FfYf@krava/T/#t
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220916071914.7156-1-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf: use kvmemdup_bpfptr helper 2022-09-16T18:58:18+00:00 Wang Yufen wangyufen@huawei.com 2022-09-13T08:40:33+00:00 a02c118ee9e898612cbae42121b9e8663455b515 Use kvmemdup_bpfptr helper instead of open-coding to simplify the code. Signed-off-by: Wang Yufen <wangyufen@huawei.com> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/1663058433-14089-1-git-send-email-wangyufen@huawei.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> 
Use kvmemdup_bpfptr helper instead of open-coding to
simplify the code.

Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/1663058433-14089-1-git-send-email-wangyufen@huawei.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
bpf: Ensure correct locking around vulnerable function find_vpid() 2022-09-16T16:00:52+00:00 Lee Jones lee@kernel.org 2022-09-12T13:38:55+00:00 83c10cc362d91c0d8d25e60779ee52fdbbf3894d The documentation for find_vpid() clearly states: "Must be called with the tasklist_lock or rcu_read_lock() held." Presently we do neither for find_vpid() instance in bpf_task_fd_query(). Add proper rcu_read_lock/unlock() to fix the issue. Fixes: 41bdc4b40ed6f ("bpf: introduce bpf subcommand BPF_TASK_FD_QUERY") Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20220912133855.1218900-1-lee@kernel.org 
The documentation for find_vpid() clearly states:

  "Must be called with the tasklist_lock or rcu_read_lock() held."

Presently we do neither for find_vpid() instance in bpf_task_fd_query().
Add proper rcu_read_lock/unlock() to fix the issue.

Fixes: 41bdc4b40ed6f ("bpf: introduce bpf subcommand BPF_TASK_FD_QUERY")
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220912133855.1218900-1-lee@kernel.org
bpf: Support kptrs in percpu arraymap 2022-09-07T18:46:08+00:00 Kumar Kartikeya Dwivedi memxor@gmail.com 2022-09-04T20:41:15+00:00 6df4ea1ff0ff70798ff1e7eed79f98ccb7b5b0a2 Enable support for kptrs in percpu BPF arraymap by wiring up the freeing of these kptrs from percpu map elements. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20220904204145.3089-3-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
Enable support for kptrs in percpu BPF arraymap by wiring up the freeing
of these kptrs from percpu map elements.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220904204145.3089-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf: Fix resetting logic for unreferenced kptrs 2022-09-07T18:15:18+00:00 Jules Irenge jbi.octave@gmail.com 2022-09-07T15:24:20+00:00 9fad7fe5b29803584c7f17a2abe6c2936fec6828 Sparse reported a warning at bpf_map_free_kptrs() "warning: Using plain integer as NULL pointer" During the process of fixing this warning, it was discovered that the current code erroneously writes to the pointer variable instead of deferencing and writing to the actual kptr. Hence, Sparse tool accidentally helped to uncover this problem. Fix this by doing WRITE_ONCE(*p, 0) instead of WRITE_ONCE(p, 0). Note that the effect of this bug is that unreferenced kptrs will not be cleared during check_and_free_fields. It is not a problem if the clearing is not done during map_free stage, as there is nothing to free for them. Fixes: 14a324f6a67e ("bpf: Wire up freeing of referenced kptr") Signed-off-by: Jules Irenge <jbi.octave@gmail.com> Link: https://lore.kernel.org/r/Yxi3pJaK6UDjVJSy@playground Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
Sparse reported a warning at bpf_map_free_kptrs()
"warning: Using plain integer as NULL pointer"
During the process of fixing this warning, it was discovered that the current
code erroneously writes to the pointer variable instead of deferencing and
writing to the actual kptr. Hence, Sparse tool accidentally helped to uncover
this problem. Fix this by doing WRITE_ONCE(*p, 0) instead of WRITE_ONCE(p, 0).

Note that the effect of this bug is that unreferenced kptrs will not be cleared
during check_and_free_fields. It is not a problem if the clearing is not done
during map_free stage, as there is nothing to free for them.

Fixes: 14a324f6a67e ("bpf: Wire up freeing of referenced kptr")
Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Link: https://lore.kernel.org/r/Yxi3pJaK6UDjVJSy@playground
Signed-off-by: Alexei Starovoitov <ast@kernel.org>