6.16-stable review patch. If anyone has any objections, please let me know.
------------------
From: Gabriele Monaco gmonaco@redhat.com
[ Upstream commit 7f904ff6e58d398c4336f3c19c42b338324451f7 ]
Using DA monitors tracepoints with KASAN enabled triggers the following warning:
BUG: KASAN: global-out-of-bounds in do_trace_event_raw_event_event_da_monitor+0xd6/0x1a0 Read of size 32 at addr ffffffffaada8980 by task ... Call Trace: <TASK> [...] do_trace_event_raw_event_event_da_monitor+0xd6/0x1a0 ? __pfx_do_trace_event_raw_event_event_da_monitor+0x10/0x10 ? trace_event_sncid+0x83/0x200 trace_event_sncid+0x163/0x200 [...] The buggy address belongs to the variable: automaton_snep+0x4e0/0x5e0
This is caused by the tracepoints reading 32 bytes __array instead of __string from the automata definition. Such strings are literals and reading 32 bytes ends up in out of bound memory accesses (e.g. the next automaton's data in this case). The error is harmless as, while printing the string, we stop at the null terminator, but it should still be fixed.
Use the __string facilities while defining the tracepoints to avoid reading out of bound memory.
Cc: Masami Hiramatsu mhiramat@kernel.org Cc: Ingo Molnar mingo@redhat.com Cc: Peter Zijlstra peterz@infradead.org Cc: Tomas Glozar tglozar@redhat.com Cc: Juri Lelli jlelli@redhat.com Cc: Clark Williams williams@redhat.com Cc: John Kacur jkacur@redhat.com Link: https://lore.kernel.org/20250728135022.255578-4-gmonaco@redhat.com Fixes: 792575348ff7 ("rv/include: Add deterministic automata monitor definition via C macros") Reviewed-by: Nam Cao namcao@linutronix.de Signed-off-by: Gabriele Monaco gmonaco@redhat.com Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/trace/rv/rv_trace.h | 76 +++++++++++++++++++------------------- 1 file changed, 38 insertions(+), 38 deletions(-)
diff --git a/kernel/trace/rv/rv_trace.h b/kernel/trace/rv/rv_trace.h index 18fa0e358a30..01fa84824bcb 100644 --- a/kernel/trace/rv/rv_trace.h +++ b/kernel/trace/rv/rv_trace.h @@ -16,23 +16,23 @@ DECLARE_EVENT_CLASS(event_da_monitor, TP_ARGS(state, event, next_state, final_state),
TP_STRUCT__entry( - __array( char, state, MAX_DA_NAME_LEN ) - __array( char, event, MAX_DA_NAME_LEN ) - __array( char, next_state, MAX_DA_NAME_LEN ) - __field( bool, final_state ) + __string( state, state ) + __string( event, event ) + __string( next_state, next_state ) + __field( bool, final_state ) ),
TP_fast_assign( - memcpy(__entry->state, state, MAX_DA_NAME_LEN); - memcpy(__entry->event, event, MAX_DA_NAME_LEN); - memcpy(__entry->next_state, next_state, MAX_DA_NAME_LEN); - __entry->final_state = final_state; + __assign_str(state); + __assign_str(event); + __assign_str(next_state); + __entry->final_state = final_state; ),
TP_printk("%s x %s -> %s%s", - __entry->state, - __entry->event, - __entry->next_state, + __get_str(state), + __get_str(event), + __get_str(next_state), __entry->final_state ? " (final)" : "") );
@@ -43,18 +43,18 @@ DECLARE_EVENT_CLASS(error_da_monitor, TP_ARGS(state, event),
TP_STRUCT__entry( - __array( char, state, MAX_DA_NAME_LEN ) - __array( char, event, MAX_DA_NAME_LEN ) + __string( state, state ) + __string( event, event ) ),
TP_fast_assign( - memcpy(__entry->state, state, MAX_DA_NAME_LEN); - memcpy(__entry->event, event, MAX_DA_NAME_LEN); + __assign_str(state); + __assign_str(event); ),
TP_printk("event %s not expected in the state %s", - __entry->event, - __entry->state) + __get_str(event), + __get_str(state)) );
#include <monitors/wip/wip_trace.h> @@ -75,26 +75,26 @@ DECLARE_EVENT_CLASS(event_da_monitor_id, TP_ARGS(id, state, event, next_state, final_state),
TP_STRUCT__entry( - __field( int, id ) - __array( char, state, MAX_DA_NAME_LEN ) - __array( char, event, MAX_DA_NAME_LEN ) - __array( char, next_state, MAX_DA_NAME_LEN ) - __field( bool, final_state ) + __field( int, id ) + __string( state, state ) + __string( event, event ) + __string( next_state, next_state ) + __field( bool, final_state ) ),
TP_fast_assign( - memcpy(__entry->state, state, MAX_DA_NAME_LEN); - memcpy(__entry->event, event, MAX_DA_NAME_LEN); - memcpy(__entry->next_state, next_state, MAX_DA_NAME_LEN); - __entry->id = id; - __entry->final_state = final_state; + __assign_str(state); + __assign_str(event); + __assign_str(next_state); + __entry->id = id; + __entry->final_state = final_state; ),
TP_printk("%d: %s x %s -> %s%s", __entry->id, - __entry->state, - __entry->event, - __entry->next_state, + __get_str(state), + __get_str(event), + __get_str(next_state), __entry->final_state ? " (final)" : "") );
@@ -105,21 +105,21 @@ DECLARE_EVENT_CLASS(error_da_monitor_id, TP_ARGS(id, state, event),
TP_STRUCT__entry( - __field( int, id ) - __array( char, state, MAX_DA_NAME_LEN ) - __array( char, event, MAX_DA_NAME_LEN ) + __field( int, id ) + __string( state, state ) + __string( event, event ) ),
TP_fast_assign( - memcpy(__entry->state, state, MAX_DA_NAME_LEN); - memcpy(__entry->event, event, MAX_DA_NAME_LEN); - __entry->id = id; + __assign_str(state); + __assign_str(event); + __entry->id = id; ),
TP_printk("%d: event %s not expected in the state %s", __entry->id, - __entry->event, - __entry->state) + __get_str(event), + __get_str(state)) );
#include <monitors/wwnr/wwnr_trace.h>