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authorSteven Rostedt (VMware)2021-03-30 09:58:38 -0400
committerSteven Rostedt (VMware)2021-03-30 09:58:38 -0400
commit59300b36f85f254260c81d9dd09195fa49eb0f98 (patch)
treea02466a8f75a624be15ce48ec686cab9d387782b /kernel
parent83b62687a05205847d627f29126a8fee3c644335 (diff)
ftrace: Check if pages were allocated before calling free_pages()
It is possible that on error pg->size can be zero when getting its order, which would return a -1 value. It is dangerous to pass in an order of -1 to free_pages(). Check if order is greater than or equal to zero before calling free_pages(). Link: https://lore.kernel.org/lkml/20210330093916.432697c7@gandalf.local.home/ Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/ftrace.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 4d8e35575549..12223132eff4 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3231,7 +3231,8 @@ ftrace_allocate_pages(unsigned long num_to_init)
pg = start_pg;
while (pg) {
order = get_count_order(pg->size / ENTRIES_PER_PAGE);
- free_pages((unsigned long)pg->records, order);
+ if (order >= 0)
+ free_pages((unsigned long)pg->records, order);
start_pg = pg->next;
kfree(pg);
pg = start_pg;
@@ -6418,7 +6419,8 @@ void ftrace_release_mod(struct module *mod)
clear_mod_from_hashes(pg);
order = get_count_order(pg->size / ENTRIES_PER_PAGE);
- free_pages((unsigned long)pg->records, order);
+ if (order >= 0)
+ free_pages((unsigned long)pg->records, order);
tmp_page = pg->next;
kfree(pg);
ftrace_number_of_pages -= 1 << order;
@@ -6778,7 +6780,8 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
if (!pg->index) {
*last_pg = pg->next;
order = get_count_order(pg->size / ENTRIES_PER_PAGE);
- free_pages((unsigned long)pg->records, order);
+ if (order >= 0)
+ free_pages((unsigned long)pg->records, order);
ftrace_number_of_pages -= 1 << order;
ftrace_number_of_groups--;
kfree(pg);