From a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255 Mon Sep 17 00:00:00 2001 From: Jinke Han Date: Tue, 8 Sep 2026 15:37:42 +0800 Subject: x86/kprobes: Fix crash when probing CS CALL instructions When using eBPF to probe CS CALL instructions within a function, a crash can be triggered. The eBPF tool probes offset 257 of the __hrtimer_run_queues() function: <__hrtimer_run_queues+249>: nopl 0x0(%rax,%rax,1) <__hrtimer_run_queues+254>: mov %r14,%rdi <__hrtimer_run_queues+257>: cs call <__x86_indirect_thunk_r12> <__hrtimer_run_queues+263>: mov %eax,%r12d <__hrtimer_run_queues+266>: xchg %ax,%ax <__hrtimer_run_queues+268>: mov %r13,%rdi Which triggers this crash: BUG: unable to handle page fault for address: 00000000000f41c9 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP NOPTI CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P RIP: 0010:__hrtimer_run_queues+0x106/0x230 Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is at the 6th byte of the above CS CALL instruction. Since the CS CALL instruction occupies 6 bytes, the exception occurred in the middle of that call instruction. The root cause is that when using eBPF tools to probe in the middle of a function, a kprobe with INT3 is used as the underlying implementation. During single-step emulation of the original CALL instruction, int3_emulate_call() assumes that the probed CALL instruction is 5 bytes long. However, the actual CS-prefixed CALL instruction occupies 6 bytes, so it constructs an incorrect exception return address. When the CPU returns from the kprobe handler, the next instruction to be executed is at the address of the last byte of that CS CALL instruction. Coincidentally, starting from that address, the CPU fetches and decodes a completely different instruction, which ultimately triggers a kernel crash. Fix the issue by using the actual instruction length obtained from the instruction decoder when constructing the exception return address, rather than relying on the hardcoded CALL_INSN_SIZE macro. [ mingo: Refined the changelog ] Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step") Suggested-by: Masami Hiramatsu (Google) Signed-off-by: Jinke Han Signed-off-by: Ingo Molnar Reviewed-by: Masami Hiramatsu (Google) Acked-by: Yafang Shao Acked-by: Borislav Petkov Cc: Peter Zijlstra Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000 --- drivers/accessibility/speakup/speakupmap.map | 93 ++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) create mode 100644 drivers/accessibility/speakup/speakupmap.map (limited to 'drivers/accessibility/speakup/speakupmap.map') diff --git a/drivers/accessibility/speakup/speakupmap.map b/drivers/accessibility/speakup/speakupmap.map new file mode 100644 index 000000000..f10d44cf5 --- /dev/null +++ b/drivers/accessibility/speakup/speakupmap.map @@ -0,0 +1,93 @@ +spk key_f9 = punc_level_dec +spk key_f10 = punc_level_inc +spk key_f11 = reading_punc_dec +spk key_f12 = reading_punc_inc +spk key_1 = vol_dec +spk key_2 = vol_inc +spk key_3 = pitch_dec +spk key_4 = pitch_inc +spk key_5 = rate_dec +spk key_6 = rate_inc +key_kpasterisk = toggle_cursoring +ctrl spk key_8 = toggle_cursoring +spk key_kpasterisk = speakup_goto +spk key_f1 = speakup_help +spk key_f2 = set_win +spk key_f3 = clear_win +spk key_f4 = enable_win +spk key_f5 = edit_some +spk key_f6 = edit_most +spk key_f7 = edit_delim +spk key_f8 = edit_repeat +shift spk key_f9 = edit_exnum + key_kp7 = say_prev_line +spk key_kp7 = left_edge + key_kp8 = say_line +double key_kp8 = say_line_indent +spk key_kp8 = say_from_top + key_kp9 = say_next_line +spk key_kp9 = top_edge + key_kpminus = speakup_parked +spk key_kpminus = say_char_num + key_kp4 = say_prev_word +spk key_kp4 = say_from_left + key_kp5 = say_word +double key_kp5 = spell_word +spk key_kp5 = spell_phonetic + key_kp6 = say_next_word +spk key_kp6 = say_to_right + key_kpplus = say_screen +spk key_kpplus = say_win + key_kp1 = say_prev_char +spk key_kp1 = right_edge + key_kp2 = say_char +spk key_kp2 = say_to_bottom +double key_kp2 = say_phonetic_char + key_kp3 = say_next_char +spk key_kp3 = bottom_edge + key_kp0 = spk_key + key_kpdot = say_position +spk key_kpdot = say_attributes +key_kpenter = speakup_quiet +spk key_kpenter = speakup_off +key_sysrq = speech_kill + key_kpslash = speakup_cut +spk key_kpslash = speakup_paste +spk key_pageup = say_first_char +spk key_pagedown = say_last_char +key_capslock = spk_key + spk key_z = spk_lock +key_leftmeta = spk_key +ctrl spk key_0 = speakup_goto +spk key_u = say_prev_line +spk key_i = say_line +double spk key_i = say_line_indent +spk key_o = say_next_line +spk key_minus = speakup_parked +shift spk key_minus = say_char_num +spk key_j = say_prev_word +spk key_k = say_word +double spk key_k = spell_word +spk key_l = say_next_word +spk key_m = say_prev_char +spk key_comma = say_char +double spk key_comma = say_phonetic_char +spk key_dot = say_next_char +spk key_n = say_position + ctrl spk key_m = left_edge + ctrl spk key_y = top_edge + ctrl spk key_dot = right_edge +ctrl spk key_p = bottom_edge +spk key_apostrophe = say_screen +spk key_h = say_from_left +spk key_y = say_from_top +spk key_semicolon = say_to_right +spk key_p = say_to_bottom +spk key_slash = say_attributes + spk key_enter = speakup_quiet + ctrl spk key_enter = speakup_off + spk key_9 = speakup_cut +spk key_8 = speakup_paste +shift spk key_m = say_first_char + ctrl spk key_semicolon = say_last_char +spk key_r = read_all_doc -- cgit v1.3.1