From: Steven Rostedt Date: Wed, 22 Jul 2026 01:11:43 +0000 (-0400) Subject: tracing: Fix mmiotrace possible NULL dereferencing of hiter->dev X-Git-Tag: v7.2-rc5~8^2~7 X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=144f29e85702234b23d2a62abf723e6a17eb5427;p=thirdparty%2Fkernel%2Flinux.git tracing: Fix mmiotrace possible NULL dereferencing of hiter->dev If the mmio_pipe_open() fails to find a PCI device, the hiter->dev will be assigned to NULL. The mmiotrace read() function dereferences the hiter->dev if hiter exists. Change the test of the read to not only check hiter being NULL, but also the hiter->dev before dereferencing it. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260721211143.36dbd559@gandalf.local.home Fixes: f984b51e0779 ("ftrace: add mmiotrace plugin") Reported-by: Sashiko Link: https://sashiko.dev/#/patchset/20260715143604.14481-1-gaikwad.dcg%40gmail.com Signed-off-by: Steven Rostedt --- diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index 20812e7f911f..b88b8d9923ad 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -145,7 +145,7 @@ static ssize_t mmio_read(struct trace_iterator *iter, struct file *filp, goto print_out; } - if (!hiter) + if (!hiter || !hiter->dev) return 0; mmio_print_pcidev(s, hiter->dev);