From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 183EF3EB0F2; Wed, 5 Aug 2026 21:27:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785965262; cv=none; b=fGifqTAnMFR9ptP/0GtQlYecRXL/feKe7SukVr4MTMsnLRncfdBh6yGfN3gXmoZS/YMcR5EH6rbx2OFxqtunCc0Scdfj2LZPV9+9HcJvPyx/hrpb/Bhkqg4WlNiq81STYKcMsbpLu0hJ10u0f7RDq2vN7GaIvRiP8iOva/NPbCk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785965262; c=relaxed/simple; bh=wdvzTd+I7Dt/MCzYRI+XVTtFkks3lV/ZxfZuqNleLjI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ur5VrRivDoB+4TKB8bds+z24scDbYz26LQx9wYY6bVqssSBCBsAzeAVxVgVJ/cfNuIipBZiyvb1mU0Q7yw5aJcA/6GvlWAfJe4rigDuGiRosEvnbO/LqSk8pb8hp2bWGqm01dWpaEJzjkdvStD15fKFhyfWpcyHbHGmuoNfwoF0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UySGE+U7; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UySGE+U7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 36CC21F00A3A; Wed, 5 Aug 2026 21:27:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785965260; bh=se3Es46riyeapglgM3WNfK0F1LE8E3A5e3Mgto+pz/o=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=UySGE+U7Et/ydmj3PIgegeVKURagCJcvokchIEOal9hJXqxfxYdLJeMH4sIYPsZzB kgfFSry21m1xw5HEDMdJu4XpEyX9z2jIlBP2TRKOPN1BlEmUnxC5Dyz+YY0yj5bTcG g/Q33EHwEgXmp6iV3dFUtUTQLEW+zT2D2aqaETQiJYGpZkiBdpf1aK3KMM9LFSQooz gNF8BWKXCev9121Gr6nUJ5Za+GEOfW84b07CXX5gf0e6ABVJHhZrFkZUP631ckcJLx 98sNq/kaQxWgOLWOckxPaWW00ThSFRmkUlc8idVVN9lwxbvnk5Ie2ufO1hCuyoKXNX 6MYLBzRv5ER0w== From: Arnaldo Carvalho de Melo To: Namhyung Kim Cc: Ingo Molnar , Thomas Gleixner , James Clark , Jiri Olsa , Ian Rogers , Adrian Hunter , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Arnaldo Carvalho de Melo , sashiko-bot , Stephane Eranian Subject: [PATCH 05/12] perf jitdump: Check snprintf return before computing header size Date: Wed, 5 Aug 2026 18:26:55 -0300 Message-ID: <20260805212704.267779-6-acme@kernel.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260805212704.267779-1-acme@kernel.org> References: <20260805212704.267779-1-acme@kernel.org> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Arnaldo Carvalho de Melo snprintf() returns the would-have-been length on truncation. When the jitted filename exceeds PATH_MAX, the unclamped 'size' value inflates sizeof(event->mmap2.filename) - size into a massive underflow, causing the header.size computation to write an oversized header. The subsequent write to 'id = event + header.size - idr_size' then corrupts the heap. Clamp size to PATH_MAX - 1 after snprintf in both jit_repipe_code_load() and jit_repipe_code_move(). Fixes: 9b07e27f88b9 ("perf inject: Add jitdump mmap injection support") Reported-by: sashiko-bot Cc: Stephane Eranian Assisted-by: Claude:claude-opus-4.6 Reviewed-by: Ian Rogers Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/jitdump.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/tools/perf/util/jitdump.c b/tools/perf/util/jitdump.c index 078d3304d2b7ebce..d7e3dcfc63b78edb 100644 --- a/tools/perf/util/jitdump.c +++ b/tools/perf/util/jitdump.c @@ -493,6 +493,9 @@ static int jit_repipe_code_load(struct jit_buf_desc *jd, union jr_entry *jr) jd->dir, nspid, count); + /* snprintf returns would-be length on truncation, clamp to buffer */ + if (size >= sizeof(event->mmap2.filename)) + size = sizeof(event->mmap2.filename) - 1; size++; /* for \0 */ @@ -623,6 +626,9 @@ static int jit_repipe_code_move(struct jit_buf_desc *jd, union jr_entry *jr) jd->dir, nspid, jr->move.code_index); + /* snprintf returns would-be length on truncation, clamp to buffer */ + if (size >= sizeof(event->mmap2.filename)) + size = sizeof(event->mmap2.filename) - 1; size++; /* for \0 */ -- 2.55.0