From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 DC00F372235; Sat, 28 Feb 2026 17:58:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772301522; cv=none; b=sRBCBSx77UtzOengMsxuwbNhDVKbtyq+FE2E7I1ghfksIrp1yHxtDWoDcbT8h7/yl29K3LgvtaTTlSkmuV8zYQo8885ocTzfBiPFvUstZYNqYNWknMkPCY6yS/X/H5BKFln8eJsC0ILwP1H8ljV5NDRL6pGjB/poC6nnNwbMAME= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772301522; c=relaxed/simple; bh=wCnE7cEyShlxOeQ+GQYspjb7N7YcTMi/8A5wfEM+Tc4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UcZ6WrkXDklo8DFDrScsrwDzKWyg6LgvyMn97IRI0LZJPUaNRCcHCYbrtlze+mb4TQNJPA0SscOUstqbgLnb0ytWvKHy+nqreZvOsPA3WNMYcWs+1ZUkWPERHaD77GJnclAlJczC8dVVJKfOK8hGxKbztA0mepfGRxZzAZvPlGI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rWl1d6i0; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="rWl1d6i0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D796BC116D0; Sat, 28 Feb 2026 17:58:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772301522; bh=wCnE7cEyShlxOeQ+GQYspjb7N7YcTMi/8A5wfEM+Tc4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rWl1d6i0zzifWnKzRkUXt6frbF4vinErvrK+r9DGbOnT4nZQ8nxCFEL9hiWETYhvX xqD38y5JH9QhtzNISCo88A1WjtHhuVb1kQMWZhFEoPwPA60LJ9lnNSReEA7Grb0yjv Y3chxX7Nd/VH5KPp1MSqXQX2VocDW/pYt+jjv9PTKGX6W8IXpKM49tF6KhJya6KVRq yjCrCC0syE8rWlM9VX9b9wWy7zqZz7KTjN1/Kx3nyjhUuzKDDFF5+7UG5yt3JiPcnV 8oQw3HTb/f65zzP7izXkp3WR1cPJk8C6w43/33zBTVPWXHEnO5N9YnCfAT1hxogJBH 0RTW2uGsJD1Cg== From: Sasha Levin To: patches@lists.linux.dev Cc: Andrii Nakryiko , Ruikai Peng , Thomas Gleixner , Shakeel Butt , syzbot+237b5b985b78c1da9600@syzkaller.appspotmail.com, stable@vger.kernel.org, Andrew Morton , Sasha Levin Subject: [PATCH 6.18 707/752] procfs: fix possible double mmput() in do_procmap_query() Date: Sat, 28 Feb 2026 12:46:58 -0500 Message-ID: <20260228174750.1542406-707-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260228174750.1542406-1-sashal@kernel.org> References: <20260228174750.1542406-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Andrii Nakryiko [ Upstream commit 61dc9f776705d6db6847c101b98fa4f0e9eb6fa3 ] When user provides incorrectly sized buffer for build ID for PROCMAP_QUERY we return with -ENAMETOOLONG error. After recent changes this condition happens later, after we unlocked mmap_lock/per-VMA lock and did mmput(), so original goto out is now wrong and will double-mmput() mm_struct. Fix by jumping further to clean up only vm_file and name_buf. Link: https://lkml.kernel.org/r/20260210192738.3041609-1-andrii@kernel.org Fixes: b5cbacd7f86f ("procfs: avoid fetching build ID while holding VMA lock") Signed-off-by: Andrii Nakryiko Reported-by: Ruikai Peng Reported-by: Thomas Gleixner Tested-by: Thomas Gleixner Reviewed-by: Shakeel Butt Reported-by: syzbot+237b5b985b78c1da9600@syzkaller.appspotmail.com Cc: Ruikai Peng Closes: https://lkml.kernel.org/r/CAFD3drOJANTZPuyiqMdqpiRwOKnHwv5QgMNZghCDr-WxdiHvMg@mail.gmail.com Closes: https://lore.kernel.org/all/698aaf3c.050a0220.3b3015.0088.GAE@google.com/T/#u Cc: Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin --- fs/proc/task_mmu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 2ee152a318f50..b490245ff9be7 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -780,7 +780,7 @@ static int do_procmap_query(struct mm_struct *mm, void __user *uarg) } else { if (karg.build_id_size < build_id_sz) { err = -ENAMETOOLONG; - goto out; + goto out_file; } karg.build_id_size = build_id_sz; } @@ -808,6 +808,7 @@ static int do_procmap_query(struct mm_struct *mm, void __user *uarg) out: query_vma_teardown(&lock_ctx); mmput(mm); +out_file: if (vm_file) fput(vm_file); kfree(name_buf); -- 2.51.0