The return value from `__rb_map_vma()`, which rejects writable or executable mappings (VM_WRITE, VM_EXEC, or !VM_MAYSHARE), was being ignored. As a result the caller of `__rb_map_vma` always returned 0 even when the mapping had actually failed, allowing it to proceed with an invalid VMA.
Reported-by: [email protected] Closes: https://syzkaller.appspot.com/bug?id=194151be8eaebd826005329b2e123aecae714bdb Signed-off-by: Ankit Khushwaha <[email protected]> Changes in v2: * applied minor cleanup suggested by Steve in v1 --- kernel/trace/ring_buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 43460949ad3f..1244d2c5c384 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -7273,7 +7273,7 @@ int ring_buffer_map(struct trace_buffer *buffer, int cpu, atomic_dec(&cpu_buffer->resize_disabled); } - return 0; + return err; } int ring_buffer_unmap(struct trace_buffer *buffer, int cpu) -- 2.51.0
