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 16EF98837; Mon, 28 Oct 2024 06:47:34 +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=1730098054; cv=none; b=YxUC2PqqJdED1ix8rR2akbKNpXg4x1KBD31Z6T7SEoeDQLbEgYyBelYzJlFJ56Ustei82lSK2V2dl9p3NBL4SDW7o45nGJMZ+uGJW5XidnUV6RLI+pbJaOrg7XKUEnodFKVKAMLeRXpr6NcufHJjEm922GPe0rVABvr3CmW6IVE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730098054; c=relaxed/simple; bh=qyFlKVMBjnhGadEqmkAzWyW9zeXsNuSi51+T8kjSo6E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LBPUJkUpR2jaIRRMksQSjbrmjQUHTvSp6JizuOfSmgEHYFqSbUQciixxICcxJqLAp3zbyPSSEJPP6eZoR3pviKDXF566NctJSP8fWos27/2Ss+HwoTeE4rMzfHa8AhaZmQ1u5FbB2+FBH5muI8kwmlUjOoxtynPVqcb99nHWsxY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=F9ldZRRB; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="F9ldZRRB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ACC56C4CEC3; Mon, 28 Oct 2024 06:47:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1730098054; bh=qyFlKVMBjnhGadEqmkAzWyW9zeXsNuSi51+T8kjSo6E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=F9ldZRRBT5mkOOP5Dpw2A0njyLNgMwEcoINYse52dVbjuMLal1jVcrCoJA4M/ZahG 2yHI3+8+80BLa6rfvYrHE5P/01us/Ro4zi0OkWLEQx1RhtHc3hozElYd2QsmWGNlkc tAcN9SXwlqhO9m9QHA98cQuN+wBA4a9/r7Q6ZGv0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Douglas Anderson , Abhinav Kumar , Sasha Levin Subject: [PATCH 6.11 055/261] drm/msm: Avoid NULL dereference in msm_disp_state_print_regs() Date: Mon, 28 Oct 2024 07:23:17 +0100 Message-ID: <20241028062313.393627097@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241028062312.001273460@linuxfoundation.org> References: <20241028062312.001273460@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Douglas Anderson [ Upstream commit 293f53263266bc4340d777268ab4328a97f041fa ] If the allocation in msm_disp_state_dump_regs() failed then `block->state` can be NULL. The msm_disp_state_print_regs() function _does_ have code to try to handle it with: if (*reg) dump_addr = *reg; ...but since "dump_addr" is initialized to NULL the above is actually a noop. The code then goes on to dereference `dump_addr`. Make the function print "Registers not stored" when it sees a NULL to solve this. Since we're touching the code, fix msm_disp_state_print_regs() not to pointlessly take a double-pointer and properly mark the pointer as `const`. Fixes: 98659487b845 ("drm/msm: add support to take dpu snapshot") Signed-off-by: Douglas Anderson Reviewed-by: Abhinav Kumar Patchwork: https://patchwork.freedesktop.org/patch/619657/ Link: https://lore.kernel.org/r/20241014093605.1.Ia1217cecec9ef09eb3c6d125360cc6c8574b0e73@changeid Signed-off-by: Abhinav Kumar Signed-off-by: Sasha Levin --- drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c b/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c index add72bbc28b17..bb149281d31fa 100644 --- a/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c +++ b/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c @@ -48,20 +48,21 @@ static void msm_disp_state_dump_regs(u32 **reg, u32 aligned_len, void __iomem *b } } -static void msm_disp_state_print_regs(u32 **reg, u32 len, void __iomem *base_addr, - struct drm_printer *p) +static void msm_disp_state_print_regs(const u32 *dump_addr, u32 len, + void __iomem *base_addr, struct drm_printer *p) { int i; - u32 *dump_addr = NULL; void __iomem *addr; u32 num_rows; + if (!dump_addr) { + drm_printf(p, "Registers not stored\n"); + return; + } + addr = base_addr; num_rows = len / REG_DUMP_ALIGN; - if (*reg) - dump_addr = *reg; - for (i = 0; i < num_rows; i++) { drm_printf(p, "0x%lx : %08x %08x %08x %08x\n", (unsigned long)(addr - base_addr), @@ -89,7 +90,7 @@ void msm_disp_state_print(struct msm_disp_state *state, struct drm_printer *p) list_for_each_entry_safe(block, tmp, &state->blocks, node) { drm_printf(p, "====================%s================\n", block->name); - msm_disp_state_print_regs(&block->state, block->size, block->base_addr, p); + msm_disp_state_print_regs(block->state, block->size, block->base_addr, p); } drm_printf(p, "===================dpu drm state================\n"); -- 2.43.0