user/sven/linux.git/kernel/trace/bpf_trace.c, branch v6.1.66

fprobe: Pass entry_data to handlers

2023-10-25T10:03:12Z

[ Upstream commit 76d0de5729c0569c4071e7f21fcab394e502f03a ] Pass the private entry_data to the entry and exit handlers so that they can share the context data, something like saved function arguments etc. User must specify the private entry_data size by @entry_data_size field before registering the fprobe. Link: https://lkml.kernel.org/r/167526696173.433354.17408372048319432574.stgit@mhiramat.roam.corp.google.com Cc: Florent Revest Cc: Mark Rutland Cc: Will Deacon Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) Stable-dep-of: 700b2b439766 ("fprobe: Fix to ensure the number of active retprobes is not zero") Signed-off-by: Sasha Levin

bpf: Add override check to kprobe multi link attach

2023-10-06T12:57:04Z

commit 41bc46c12a8053a1b3279a379bd6b5e87b045b85 upstream. Currently the multi_kprobe link attach does not check error injection list for programs with bpf_override_return helper and allows them to attach anywhere. Adding the missing check. Fixes: 0dcac2725406 ("bpf: Add multi kprobe link") Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Reviewed-by: Alan Maguire Cc: stable@vger.kernel.org Link: https://lore.kernel.org/bpf/20230907200652.926951-1-jolsa@kernel.org Signed-off-by: Greg Kroah-Hartman

bpf: Clear the probe_addr for uprobe

2023-09-13T07:42:30Z

[ Upstream commit 5125e757e62f6c1d5478db4c2b61a744060ddf3f ] To avoid returning uninitialized or random values when querying the file descriptor (fd) and accessing probe_addr, it is necessary to clear the variable prior to its use. Fixes: 41bdc4b40ed6 ("bpf: introduce bpf subcommand BPF_TASK_FD_QUERY") Signed-off-by: Yafang Shao Acked-by: Yonghong Song Acked-by: Jiri Olsa Link: https://lore.kernel.org/r/20230709025630.3735-6-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

bpf: Disable preemption in bpf_event_output

2023-08-11T10:08:21Z

commit d62cc390c2e99ae267ffe4b8d7e2e08b6c758c32 upstream. We received report [1] of kernel crash, which is caused by using nesting protection without disabled preemption. The bpf_event_output can be called by programs executed by bpf_prog_run_array_cg function that disabled migration but keeps preemption enabled. This can cause task to be preempted by another one inside the nesting protection and lead eventually to two tasks using same perf_sample_data buffer and cause crashes like: BUG: kernel NULL pointer dereference, address: 0000000000000001 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page ... ? perf_output_sample+0x12a/0x9a0 ? finish_task_switch.isra.0+0x81/0x280 ? perf_event_output+0x66/0xa0 ? bpf_event_output+0x13a/0x190 ? bpf_event_output_data+0x22/0x40 ? bpf_prog_dfc84bbde731b257_cil_sock4_connect+0x40a/0xacb ? xa_load+0x87/0xe0 ? __cgroup_bpf_run_filter_sock_addr+0xc1/0x1a0 ? release_sock+0x3e/0x90 ? sk_setsockopt+0x1a1/0x12f0 ? udp_pre_connect+0x36/0x50 ? inet_dgram_connect+0x93/0xa0 ? __sys_connect+0xb4/0xe0 ? udp_setsockopt+0x27/0x40 ? __pfx_udp_push_pending_frames+0x10/0x10 ? __sys_setsockopt+0xdf/0x1a0 ? __x64_sys_connect+0xf/0x20 ? do_syscall_64+0x3a/0x90 ? entry_SYSCALL_64_after_hwframe+0x72/0xdc Fixing this by disabling preemption in bpf_event_output. [1] https://github.com/cilium/cilium/issues/26756 Cc: stable@vger.kernel.org Reported-by: Oleg "livelace" Popov Closes: https://github.com/cilium/cilium/issues/26756 Fixes: 2a916f2f546c ("bpf: Use migrate_disable/enable in array macros and cgroup/lirc code.") Acked-by: Hou Tao Signed-off-by: Jiri Olsa Link: https://lore.kernel.org/r/20230725084206.580930-3-jolsa@kernel.org Signed-off-by: Alexei Starovoitov Signed-off-by: Greg Kroah-Hartman

bpf: Disable preemption in bpf_perf_event_output

2023-08-11T10:08:20Z

commit f2c67a3e60d1071b65848efaa8c3b66c363dd025 upstream. The nesting protection in bpf_perf_event_output relies on disabled preemption, which is guaranteed for kprobes and tracepoints. However bpf_perf_event_output can be also called from uprobes context through bpf_prog_run_array_sleepable function which disables migration, but keeps preemption enabled. This can cause task to be preempted by another one inside the nesting protection and lead eventually to two tasks using same perf_sample_data buffer and cause crashes like: kernel tried to execute NX-protected page - exploit attempt? (uid: 0) BUG: unable to handle page fault for address: ffffffff82be3eea ... Call Trace: ? __die+0x1f/0x70 ? page_fault_oops+0x176/0x4d0 ? exc_page_fault+0x132/0x230 ? asm_exc_page_fault+0x22/0x30 ? perf_output_sample+0x12b/0x910 ? perf_event_output+0xd0/0x1d0 ? bpf_perf_event_output+0x162/0x1d0 ? bpf_prog_c6271286d9a4c938_krava1+0x76/0x87 ? __uprobe_perf_func+0x12b/0x540 ? uprobe_dispatcher+0x2c4/0x430 ? uprobe_notify_resume+0x2da/0xce0 ? atomic_notifier_call_chain+0x7b/0x110 ? exit_to_user_mode_prepare+0x13e/0x290 ? irqentry_exit_to_user_mode+0x5/0x30 ? asm_exc_int3+0x35/0x40 Fixing this by disabling preemption in bpf_perf_event_output. Cc: stable@vger.kernel.org Fixes: 8c7dcb84e3b7 ("bpf: implement sleepable uprobes by chaining gps") Acked-by: Hou Tao Signed-off-by: Jiri Olsa Link: https://lore.kernel.org/r/20230725084206.580930-2-jolsa@kernel.org Signed-off-by: Alexei Starovoitov Signed-off-by: Greg Kroah-Hartman

bpf: Add extra path pointer check to d_path helper

2023-06-14T09:15:22Z

[ Upstream commit f46fab0e36e611a2389d3843f34658c849b6bd60 ] Anastasios reported crash on stable 5.15 kernel with following BPF attached to lsm hook: SEC("lsm.s/bprm_creds_for_exec") int BPF_PROG(bprm_creds_for_exec, struct linux_binprm *bprm) { struct path *path = &bprm->executable->f_path; char p[128] = { 0 }; bpf_d_path(path, p, 128); return 0; } But bprm->executable can be NULL, so bpf_d_path call will crash: BUG: kernel NULL pointer dereference, address: 0000000000000018 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC NOPTI ... RIP: 0010:d_path+0x22/0x280 ... Call Trace: bpf_d_path+0x21/0x60 bpf_prog_db9cf176e84498d9_bprm_creds_for_exec+0x94/0x99 bpf_trampoline_6442506293_0+0x55/0x1000 bpf_lsm_bprm_creds_for_exec+0x5/0x10 security_bprm_creds_for_exec+0x29/0x40 bprm_execve+0x1c1/0x900 do_execveat_common.isra.0+0x1af/0x260 __x64_sys_execve+0x32/0x40 It's problem for all stable trees with bpf_d_path helper, which was added in 5.9. This issue is fixed in current bpf code, where we identify and mark trusted pointers, so the above code would fail even to load. For the sake of the stable trees and to workaround potentially broken verifier in the future, adding the code that reads the path object from the passed pointer and verifies it's valid in kernel space. Fixes: 6e22ab9da793 ("bpf: Add d_path helper") Reported-by: Anastasios Papagiannis Suggested-by: Alexei Starovoitov Signed-off-by: Jiri Olsa Signed-off-by: Daniel Borkmann Acked-by: Stanislav Fomichev Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20230606181714.532998-1-jolsa@kernel.org Signed-off-by: Sasha Levin

bpf: Fix a possible task gone issue with bpf_send_signal[_thread]() helpers

2023-02-09T10:28:00Z

[ Upstream commit bdb7fdb0aca8b96cef9995d3a57e251c2289322f ] In current bpf_send_signal() and bpf_send_signal_thread() helper implementation, irq_work is used to handle nmi context. Hao Sun reported in [1] that the current task at the entry of the helper might be gone during irq_work callback processing. To fix the issue, a reference is acquired for the current task before enqueuing into the irq_work so that the queued task is still available during irq_work callback processing. [1] https://lore.kernel.org/bpf/20230109074425.12556-1-sunhao.th@gmail.com/ Fixes: 8b401f9ed244 ("bpf: implement bpf_send_signal() helper") Tested-by: Hao Sun Reported-by: Hao Sun Signed-off-by: Yonghong Song Link: https://lore.kernel.org/r/20230118204815.3331855-1-yhs@fb.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

bpf: Skip task with pid=1 in send_signal_common()

2023-02-06T07:06:31Z

[ Upstream commit a3d81bc1eaef48e34dd0b9b48eefed9e02a06451 ] The following kernel panic can be triggered when a task with pid=1 attaches a prog that attempts to send killing signal to itself, also see [1] for more details: Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b CPU: 3 PID: 1 Comm: systemd Not tainted 6.1.0-09652-g59fe41b5255f #148 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x100/0x178 lib/dump_stack.c:106 panic+0x2c4/0x60f kernel/panic.c:275 do_exit.cold+0x63/0xe4 kernel/exit.c:789 do_group_exit+0xd4/0x2a0 kernel/exit.c:950 get_signal+0x2460/0x2600 kernel/signal.c:2858 arch_do_signal_or_restart+0x78/0x5d0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd So skip task with pid=1 in bpf_send_signal_common() to avoid the panic. [1] https://lore.kernel.org/bpf/20221222043507.33037-1-sunhao.th@gmail.com Signed-off-by: Hao Sun Signed-off-by: Daniel Borkmann Acked-by: Stanislav Fomichev Link: https://lore.kernel.org/bpf/20230106084838.12690-1-sunhao.th@gmail.com Signed-off-by: Sasha Levin

bpf: Fix sample_flags for bpf_perf_event_output

2022-10-17T14:32:06Z

* Raw data is also filled by bpf_perf_event_output. * Add sample_flags to indicate raw data. * This eliminates the segfaults as shown below: Run ./samples/bpf/trace_output BUG pid 9 cookie 1001000000004 sized 4 BUG pid 9 cookie 1001000000004 sized 4 BUG pid 9 cookie 1001000000004 sized 4 Segmentation fault (core dumped) Fixes: 838d9bb62d13 ("perf: Use sample_flags for raw_data") Signed-off-by: Sumanth Korikkar Signed-off-by: Peter Zijlstra (Intel) Acked-by: Namhyung Kim Link: https://lkml.kernel.org/r/20221007081327.1047552-1-sumanthk@linux.ibm.com

Merge tag 'perf-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2022-10-10T16:27:46Z

Pull perf events updates from Ingo Molnar: "PMU driver updates: - Add AMD Last Branch Record Extension Version 2 (LbrExtV2) feature support for Zen 4 processors. - Extend the perf ABI to provide branch speculation information, if available, and use this on CPUs that have it (eg. LbrExtV2). - Improve Intel PEBS TSC timestamp handling & integration. - Add Intel Raptor Lake S CPU support. - Add 'perf mem' and 'perf c2c' memory profiling support on AMD CPUs by utilizing IBS tagged load/store samples. - Clean up & optimize various x86 PMU details. HW breakpoints: - Big rework to optimize the code for systems with hundreds of CPUs and thousands of breakpoints: - Replace the nr_bp_mutex global mutex with the bp_cpuinfo_sem per-CPU rwsem that is read-locked during most of the key operations. - Improve the O(#cpus * #tasks) logic in toggle_bp_slot() and fetch_bp_busy_slots(). - Apply micro-optimizations & cleanups. - Misc cleanups & enhancements" * tag 'perf-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (75 commits) perf/hw_breakpoint: Annotate tsk->perf_event_mutex vs ctx->mutex perf: Fix pmu_filter_match() perf: Fix lockdep_assert_event_ctx() perf/x86/amd/lbr: Adjust LBR regardless of filtering perf/x86/utils: Fix uninitialized var in get_branch_type() perf/uapi: Define PERF_MEM_SNOOPX_PEER in kernel header file perf/x86/amd: Support PERF_SAMPLE_PHY_ADDR perf/x86/amd: Support PERF_SAMPLE_ADDR perf/x86/amd: Support PERF_SAMPLE_{WEIGHT|WEIGHT_STRUCT} perf/x86/amd: Support PERF_SAMPLE_DATA_SRC perf/x86/amd: Add IBS OP_DATA2 DataSrc bit definitions perf/mem: Introduce PERF_MEM_LVLNUM_{EXTN_MEM|IO} perf/x86/uncore: Add new Raptor Lake S support perf/x86/cstate: Add new Raptor Lake S support perf/x86/msr: Add new Raptor Lake S support perf/x86: Add new Raptor Lake S support bpf: Check flags for branch stack in bpf_read_branch_records helper perf, hw_breakpoint: Fix use-after-free if perf_event_open() fails perf: Use sample_flags for raw_data perf: Use sample_flags for addr ...