6.6-stable review patch. If anyone has any objections, please let me know.
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From: Casey Chen cachen@purestorage.com
[ Upstream commit 4c17736689ccfc44ec7dcc472577f25c34cf8724 ]
With 0dd5041c9a0e ("perf addr_location: Add init/exit/copy functions"), when cpumode is 3 (macro PERF_RECORD_MISC_HYPERVISOR), thread__find_map() could return with al->maps being NULL.
The path below could add a callchain_cursor_node with NULL ms.maps.
add_callchain_ip() thread__find_symbol(.., &al) thread__find_map(.., &al) // al->maps becomes NULL ms.maps = maps__get(al.maps) callchain_cursor_append(..., &ms, ...) node->ms.maps = maps__get(ms->maps)
Then the path below would dereference NULL maps and get segfault.
fill_callchain_info() maps__machine(node->ms.maps);
Fix it by checking if maps is NULL in fill_callchain_info().
Fixes: 0dd5041c9a0e ("perf addr_location: Add init/exit/copy functions") Signed-off-by: Casey Chen cachen@purestorage.com Reviewed-by: Ian Rogers irogers@google.com Reviewed-by: Arnaldo Carvalho de Melo acme@redhat.com Acked-by: Namhyung Kim namhyung@kernel.org Cc: yzhong@purestorage.com Link: https://lore.kernel.org/r/20240722211548.61455-1-cachen@purestorage.com Signed-off-by: Namhyung Kim namhyung@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/util/callchain.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c index aee937d14fbbf..09e6b4e1401c9 100644 --- a/tools/perf/util/callchain.c +++ b/tools/perf/util/callchain.c @@ -1126,7 +1126,7 @@ int hist_entry__append_callchain(struct hist_entry *he, struct perf_sample *samp int fill_callchain_info(struct addr_location *al, struct callchain_cursor_node *node, bool hide_unresolved) { - struct machine *machine = maps__machine(node->ms.maps); + struct machine *machine = node->ms.maps ? maps__machine(node->ms.maps) : NULL;
maps__put(al->maps); al->maps = maps__get(node->ms.maps);