user/sven/linux.git/kernel/trace/trace_uprobe.c, branch v6.1.151

tracing: probes: Fix a possible race in trace_probe_log APIs

2025-05-22T12:09:59Z

[ Upstream commit fd837de3c9cb1a162c69bc1fb1f438467fe7f2f5 ] Since the shared trace_probe_log variable can be accessed and modified via probe event create operation of kprobe_events, uprobe_events, and dynamic_events, it should be protected. In the dynamic_events, all operations are serialized by `dyn_event_ops_mutex`. But kprobe_events and uprobe_events interfaces are not serialized. To solve this issue, introduces dyn_event_create(), which runs create() operation under the mutex, for kprobe_events and uprobe_events. This also uses lockdep to check the mutex is held when using trace_probe_log* APIs. Link: https://lore.kernel.org/all/174684868120.551552.3068655787654268804.stgit@devnote2/ Reported-by: Paul Cacheux Closes: https://lore.kernel.org/all/20250510074456.805a16872b591e2971a4d221@kernel.org/ Fixes: ab105a4fb894 ("tracing: Use tracing error_log with probe events") Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Sasha Levin

uprobe: avoid out-of-bounds memory access of fetching args

2024-11-17T14:07:21Z

commit 373b9338c9722a368925d83bc622c596896b328e upstream. Uprobe needs to fetch args into a percpu buffer, and then copy to ring buffer to avoid non-atomic context problem. Sometimes user-space strings, arrays can be very large, but the size of percpu buffer is only page size. And store_trace_args() won't check whether these data exceeds a single page or not, caused out-of-bounds memory access. It could be reproduced by following steps: 1. build kernel with CONFIG_KASAN enabled 2. save follow program as test.c ``` \#include \#include \#include // If string length large than MAX_STRING_SIZE, the fetch_store_strlen() // will return 0, cause __get_data_size() return shorter size, and // store_trace_args() will not trigger out-of-bounds access. // So make string length less than 4096. \#define STRLEN 4093 void generate_string(char *str, int n) { int i; for (i = 0; i < n; ++i) { char c = i % 26 + 'a'; str[i] = c; } str[n-1] = '\0'; } void print_string(char *str) { printf("%s\n", str); } int main() { char tmp[STRLEN]; generate_string(tmp, STRLEN); print_string(tmp); return 0; } ``` 3. compile program `gcc -o test test.c` 4. get the offset of `print_string()` ``` objdump -t test | grep -w print_string 0000000000401199 g F .text 000000000000001b print_string ``` 5. configure uprobe with offset 0x1199 ``` off=0x1199 cd /sys/kernel/debug/tracing/ echo "p /root/test:${off} arg1=+0(%di):ustring arg2=\$comm arg3=+0(%di):ustring" > uprobe_events echo 1 > events/uprobes/enable echo 1 > tracing_on ``` 6. run `test`, and kasan will report error. ================================================================== BUG: KASAN: use-after-free in strncpy_from_user+0x1d6/0x1f0 Write of size 8 at addr ffff88812311c004 by task test/499CPU: 0 UID: 0 PID: 499 Comm: test Not tainted 6.12.0-rc3+ #18 Hardware name: Red Hat KVM, BIOS 1.16.0-4.al8 04/01/2014 Call Trace: dump_stack_lvl+0x55/0x70 print_address_description.constprop.0+0x27/0x310 kasan_report+0x10f/0x120 ? strncpy_from_user+0x1d6/0x1f0 strncpy_from_user+0x1d6/0x1f0 ? rmqueue.constprop.0+0x70d/0x2ad0 process_fetch_insn+0xb26/0x1470 ? __pfx_process_fetch_insn+0x10/0x10 ? _raw_spin_lock+0x85/0xe0 ? __pfx__raw_spin_lock+0x10/0x10 ? __pte_offset_map+0x1f/0x2d0 ? unwind_next_frame+0xc5f/0x1f80 ? arch_stack_walk+0x68/0xf0 ? is_bpf_text_address+0x23/0x30 ? kernel_text_address.part.0+0xbb/0xd0 ? __kernel_text_address+0x66/0xb0 ? unwind_get_return_address+0x5e/0xa0 ? __pfx_stack_trace_consume_entry+0x10/0x10 ? arch_stack_walk+0xa2/0xf0 ? _raw_spin_lock_irqsave+0x8b/0xf0 ? __pfx__raw_spin_lock_irqsave+0x10/0x10 ? depot_alloc_stack+0x4c/0x1f0 ? _raw_spin_unlock_irqrestore+0xe/0x30 ? stack_depot_save_flags+0x35d/0x4f0 ? kasan_save_stack+0x34/0x50 ? kasan_save_stack+0x24/0x50 ? mutex_lock+0x91/0xe0 ? __pfx_mutex_lock+0x10/0x10 prepare_uprobe_buffer.part.0+0x2cd/0x500 uprobe_dispatcher+0x2c3/0x6a0 ? __pfx_uprobe_dispatcher+0x10/0x10 ? __kasan_slab_alloc+0x4d/0x90 handler_chain+0xdd/0x3e0 handle_swbp+0x26e/0x3d0 ? __pfx_handle_swbp+0x10/0x10 ? uprobe_pre_sstep_notifier+0x151/0x1b0 irqentry_exit_to_user_mode+0xe2/0x1b0 asm_exc_int3+0x39/0x40 RIP: 0033:0x401199 Code: 01 c2 0f b6 45 fb 88 02 83 45 fc 01 8b 45 fc 3b 45 e4 7c b7 8b 45 e4 48 98 48 8d 50 ff 48 8b 45 e8 48 01 d0 ce RSP: 002b:00007ffdf00576a8 EFLAGS: 00000206 RAX: 00007ffdf00576b0 RBX: 0000000000000000 RCX: 0000000000000ff2 RDX: 0000000000000ffc RSI: 0000000000000ffd RDI: 00007ffdf00576b0 RBP: 00007ffdf00586b0 R08: 00007feb2f9c0d20 R09: 00007feb2f9c0d20 R10: 0000000000000001 R11: 0000000000000202 R12: 0000000000401040 R13: 00007ffdf0058780 R14: 0000000000000000 R15: 0000000000000000 This commit enforces the buffer's maxlen less than a page-size to avoid store_trace_args() out-of-memory access. Link: https://lore.kernel.org/all/20241015060148.1108331-1-mqaio@linux.alibaba.com/ Fixes: dcad1a204f72 ("tracing/uprobes: Fetch args before reserving a ring buffer") Signed-off-by: Qiao Ma Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Sasha Levin Signed-off-by: Vamsi Krishna Brahmajosyula Signed-off-by: Greg Kroah-Hartman

uprobes: encapsulate preparation of uprobe args buffer

2024-11-17T14:07:21Z

commit 3eaea21b4d27cff0017c20549aeb53034c58fc23 upstream. Move the logic of fetching temporary per-CPU uprobe buffer and storing uprobes args into it to a new helper function. Store data size as part of this buffer, simplifying interfaces a bit, as now we only pass single uprobe_cpu_buffer reference around, instead of pointer + dsize. This logic was duplicated across uprobe_dispatcher and uretprobe_dispatcher, and now will be centralized. All this is also in preparation to make this uprobe_cpu_buffer handling logic optional in the next patch. Link: https://lore.kernel.org/all/20240318181728.2795838-2-andrii@kernel.org/ [Masami: update for v6.9-rc3 kernel] Signed-off-by: Andrii Nakryiko Reviewed-by: Jiri Olsa Acked-by: Masami Hiramatsu (Google) Signed-off-by: Masami Hiramatsu (Google) Stable-dep-of: 373b9338c972 ("uprobe: avoid out-of-bounds memory access of fetching args") Signed-off-by: Sasha Levin Signed-off-by: Vamsi Krishna Brahmajosyula 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

tracing/probes: Fix to record 0-length data_loc in fetch_store_string*() if fails

2023-08-03T08:23:55Z

[ Upstream commit 797311bce5c2ac90b8d65e357603cfd410d36ebb ] Fix to record 0-length data to data_loc in fetch_store_string*() if it fails to get the string data. Currently those expect that the data_loc is updated by store_trace_args() if it returns the error code. However, that does not work correctly if the argument is an array of strings. In that case, store_trace_args() only clears the first entry of the array (which may have no error) and leaves other entries. So it should be cleared by fetch_store_string*() itself. Also, 'dyndata' and 'maxlen' in store_trace_args() should be updated only if it is used (ret > 0 and argument is a dynamic data.) Link: https://lore.kernel.org/all/168908496683.123124.4761206188794205601.stgit@devnote2/ Fixes: 40b53b771806 ("tracing: probeevent: Add array type support") Cc: stable@vger.kernel.org Reviewed-by: Steven Rostedt (Google) Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Sasha Levin

Merge tag 'trace-v6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2022-08-05T16:41:12Z

Pull tracing updates from Steven Rostedt: - Runtime verification infrastructure This is the biggest change here. It introduces the runtime verification that is necessary for running Linux on safety critical systems. It allows for deterministic automata models to be inserted into the kernel that will attach to tracepoints, where the information on these tracepoints will move the model from state to state. If a state is encountered that does not belong to the model, it will then activate a given reactor, that could just inform the user or even panic the kernel (for which safety critical systems will detect and can recover from). - Two monitor models are also added: Wakeup In Preemptive (WIP - not to be confused with "work in progress"), and Wakeup While Not Running (WWNR). - Added __vstring() helper to the TRACE_EVENT() macro to replace several vsnprintf() usages that were all doing it wrong. - eprobes now can have their event autogenerated when the event name is left off. - The rest is various cleanups and fixes. * tag 'trace-v6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (50 commits) rv: Unlock on error path in rv_unregister_reactor() tracing: Use alignof__(struct {type b;}) instead of offsetof() tracing/eprobe: Show syntax error logs in error_log file scripts/tracing: Fix typo 'the the' in comment tracepoints: It is CONFIG_TRACEPOINTS not CONFIG_TRACEPOINT tracing: Use free_trace_buffer() in allocate_trace_buffers() tracing: Use a struct alignof to determine trace event field alignment rv/reactor: Add the panic reactor rv/reactor: Add the printk reactor rv/monitor: Add the wwnr monitor rv/monitor: Add the wip monitor rv/monitor: Add the wip monitor skeleton created by dot2k Documentation/rv: Add deterministic automata instrumentation documentation Documentation/rv: Add deterministic automata monitor synthesis documentation tools/rv: Add dot2k Documentation/rv: Add deterministic automaton documentation tools/rv: Add dot2c Documentation/rv: Add a basic documentation rv/include: Add instrumentation helper functions rv/include: Add deterministic automata monitor definition via C macros ...

tracing: Auto generate event name when creating a group of events

2022-07-24T23:11:17Z

Currently when creating a specific group of trace events, take kprobe event as example, the user must use the following format: p:GRP/EVENT [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS], which means user must enter EVENT name, one example is: echo 'p:usb_gadget/config_usb_cfg_link config_usb_cfg_link $arg1' >> kprobe_events It is not simple if there are too many entries because the event name is the same as symbol name. This change allows user to specify no EVENT name, format changed as: p:GRP/ [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] It will generate event name automatically and one example is: echo 'p:usb_gadget/ config_usb_cfg_link $arg1' >> kprobe_events. Link: https://lore.kernel.org/all/1656296348-16111-4-git-send-email-quic_linyyuan@quicinc.com/ Acked-by: Masami Hiramatsu (Google) Reviewed-by: Tom Zanussi Signed-off-by: Linyu Yuan Signed-off-by: Steven Rostedt (Google)

Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2022-07-09T19:24:16Z

Daniel Borkmann says: ==================== pull-request: bpf-next 2022-07-09 We've added 94 non-merge commits during the last 19 day(s) which contain a total of 125 files changed, 5141 insertions(+), 6701 deletions(-). The main changes are: 1) Add new way for performing BTF type queries to BPF, from Daniel Müller. 2) Add inlining of calls to bpf_loop() helper when its function callback is statically known, from Eduard Zingerman. 3) Implement BPF TCP CC framework usability improvements, from Jörn-Thorben Hinz. 4) Add LSM flavor for attaching per-cgroup BPF programs to existing LSM hooks, from Stanislav Fomichev. 5) Remove all deprecated libbpf APIs in prep for 1.0 release, from Andrii Nakryiko. 6) Add benchmarks around local_storage to BPF selftests, from Dave Marchevsky. 7) AF_XDP sample removal (given move to libxdp) and various improvements around AF_XDP selftests, from Magnus Karlsson & Maciej Fijalkowski. 8) Add bpftool improvements for memcg probing and bash completion, from Quentin Monnet. 9) Add arm64 JIT support for BPF-2-BPF coupled with tail calls, from Jakub Sitnicki. 10) Sockmap optimizations around throughput of UDP transmissions which have been improved by 61%, from Cong Wang. 11) Rework perf's BPF prologue code to remove deprecated functions, from Jiri Olsa. 12) Fix sockmap teardown path to avoid sleepable sk_psock_stop, from John Fastabend. 13) Fix libbpf's cleanup around legacy kprobe/uprobe on error case, from Chuang Wang. 14) Fix libbpf's bpf_helpers.h to work with gcc for the case of its sec/pragma macro, from James Hilliard. 15) Fix libbpf's pt_regs macros for riscv to use a0 for RC register, from Yixun Lan. 16) Fix bpftool to show the name of type BPF_OBJ_LINK, from Yafang Shao. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (94 commits) selftests/bpf: Fix xdp_synproxy build failure if CONFIG_NF_CONNTRACK=m/n bpf: Correctly propagate errors up from bpf_core_composites_match libbpf: Disable SEC pragma macro on GCC bpf: Check attach_func_proto more carefully in check_return_code selftests/bpf: Add test involving restrict type qualifier bpftool: Add support for KIND_RESTRICT to gen min_core_btf command MAINTAINERS: Add entry for AF_XDP selftests files selftests, xsk: Rename AF_XDP testing app bpf, docs: Remove deprecated xsk libbpf APIs description selftests/bpf: Add benchmark for local_storage RCU Tasks Trace usage libbpf, riscv: Use a0 for RC register libbpf: Remove unnecessary usdt_rel_ip assignments selftests/bpf: Fix few more compiler warnings selftests/bpf: Fix bogus uninitialized variable warning bpftool: Remove zlib feature test from Makefile libbpf: Cleanup the legacy uprobe_event on failed add/attach_event() libbpf: Fix wrong variable used in perf_event_uprobe_open_legacy() libbpf: Cleanup the legacy kprobe_event on failed add/attach_event() selftests/bpf: Add type match test against kernel's task_struct selftests/bpf: Add nested type to type based tests ... ==================== Link: https://lore.kernel.org/r/20220708233145.32365-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2022-06-30T23:31:00Z

drivers/net/ethernet/microchip/sparx5/sparx5_switchdev.c 9c5de246c1db ("net: sparx5: mdb add/del handle non-sparx5 devices") fbb89d02e33a ("net: sparx5: Allow mdb entries to both CPU and ports") Signed-off-by: Jakub Kicinski

uprobe: gate bpf call behind BPF_EVENTS

2022-06-21T00:04:03Z

The call into bpf from uprobes needs to be gated now that it doesn't use the trace_events.h helpers. Randy found this as a randconfig build failure on linux-next [1]. [1]: https://lore.kernel.org/linux-next/2de99180-7d55-2fdf-134d-33198c27cc58@infradead.org/ Reported-by: Randy Dunlap Signed-off-by: Delyan Kratunov Tested-by: Randy Dunlap Acked-by: Randy Dunlap Link: https://lore.kernel.org/r/cb8bfbbcde87ed5d811227a393ef4925f2aadb7b.camel@fb.com Signed-off-by: Alexei Starovoitov