spmi: trace: fix stack-out-of-bound access in SPMI tracing functions

2022-08-25T09:09:25Z

commit 2af28b241eea816e6f7668d1954f15894b45d7e3 upstream. trace_spmi_write_begin() and trace_spmi_read_end() both call memcpy() with a length of "len + 1". This leads to one extra byte being read beyond the end of the specified buffer. Fix this out-of-bound memory access by using a length of "len" instead. Here is a KASAN log showing the issue: BUG: KASAN: stack-out-of-bounds in trace_event_raw_event_spmi_read_end+0x1d0/0x234 Read of size 2 at addr ffffffc0265b7540 by task thermal@2.0-ser/1314 ... Call trace: dump_backtrace+0x0/0x3e8 show_stack+0x2c/0x3c dump_stack_lvl+0xdc/0x11c print_address_description+0x74/0x384 kasan_report+0x188/0x268 kasan_check_range+0x270/0x2b0 memcpy+0x90/0xe8 trace_event_raw_event_spmi_read_end+0x1d0/0x234 spmi_read_cmd+0x294/0x3ac spmi_ext_register_readl+0x84/0x9c regmap_spmi_ext_read+0x144/0x1b0 [regmap_spmi] _regmap_raw_read+0x40c/0x754 regmap_raw_read+0x3a0/0x514 regmap_bulk_read+0x418/0x494 adc5_gen3_poll_wait_hs+0xe8/0x1e0 [qcom_spmi_adc5_gen3] ... __arm64_sys_read+0x4c/0x60 invoke_syscall+0x80/0x218 el0_svc_common+0xec/0x1c8 ... addr ffffffc0265b7540 is located in stack of task thermal@2.0-ser/1314 at offset 32 in frame: adc5_gen3_poll_wait_hs+0x0/0x1e0 [qcom_spmi_adc5_gen3] this frame has 1 object: [32, 33) 'status' Memory state around the buggy address: ffffffc0265b7400: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 ffffffc0265b7480: 04 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 >ffffffc0265b7500: 00 00 00 00 f1 f1 f1 f1 01 f3 f3 f3 00 00 00 00 ^ ffffffc0265b7580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffffc0265b7600: f1 f1 f1 f1 01 f2 07 f2 f2 f2 01 f3 00 00 00 00 ================================================================== Fixes: a9fce374815d ("spmi: add command tracepoints for SPMI") Cc: stable@vger.kernel.org Reviewed-by: Stephen Boyd Acked-by: Steven Rostedt (Google) Signed-off-by: David Collins Link: https://lore.kernel.org/r/20220627235512.2272783-1-quic_collinsd@quicinc.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

spmi: add command tracepoints for SPMI

2015-08-05T19:27:09Z

Add tracepoints to retrieve information about read, write and non-data commands. For performance measurement support tracepoints are added at the beginning and at the end of transfers. Following is a list showing the new tracepoint events. The "cmd" parameter here represents the opcode, SID, and full 16-bit address. spmi_write_begin: cmd and data buffer. spmi_write_end : cmd and return value. spmi_read_begin : cmd. spmi_read_end : cmd, return value and data buffer. spmi_cmd : cmd. The reason that cmd appears at both the beginning and at the end event is that SPMI drivers can request commands concurrently. cmd helps in matching the corresponding events. SPMI tracepoints can be enabled like: echo 1 >/sys/kernel/debug/tracing/events/spmi/enable and will dump messages that can be viewed in /sys/kernel/debug/tracing/trace that look like: ... spmi_read_begin: opc=56 sid=00 addr=0x0000 ... spmi_read_end: opc=56 sid=00 addr=0x0000 ret=0 len=02 buf=0x[01-40] ... spmi_write_begin: opc=48 sid=00 addr=0x0000 len=3 buf=0x[ff-ff-ff] Suggested-by: Sagar Dharia Acked-by: Steven Rostedt Reviewed-by: Stephen Boyd Signed-off-by: Gilad Avidov Signed-off-by: Ankit Gupta Signed-off-by: Greg Kroah-Hartman

kernel.git/include/trace/events/spmi.h, branch linux-4.9.y

spmi: trace: fix stack-out-of-bound access in SPMI tracing functions

spmi: add command tracepoints for SPMI