Re: [PATCH v2] ring buffer: Propagate __rb_map_vma return value to caller
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2025-10-09 02:11:18
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On Wed, 8 Oct 2025 22:55:16 +0530 Ankit Khushwaha [off-list ref] wrote:
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: syzbot+ddc001b92c083dbf2b97@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?id=194151be8eaebd826005329b2e123aecae714bdb Signed-off-by: Ankit Khushwaha <redacted>
Thanks for the update.
Changes in v2: * applied minor cleanup suggested by Steve in v1
Note, the "changes" should be below the "---" as that prevents it from being added to the git change log. And it's always good to include a link to the previous version. For example:
---
Changes in v2: https://lore.kernel.org/linux-trace-kernel/20251007171256.20884-1-ankitkhushwaha.linux@gmail.com/ (local) * applied minor cleanup suggested by Steve in v1 -- Steve
quoted hunk ↗ jump to hunk
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)