From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794591586; b=i+WaVRUtBjsVxXRvceq7vtrHscWbcrFCvMImkrMuJo9wcSRPwvuyMOrzw2NpTvEXU2aw 7uBZ2PiMWrCSe9oC7IoiJWyZwp8MvsVFXlRlQDg+nIVT0+St+cDcjPdLc0zOGaAFqC/1h auKLJyTdj3KIkdId2ynKqrWQlbc7nnx/j+DPwU9Ndyo/t+ussCgGXFyundUMH03Sy6C1C VU57u8m0WoOCmgzFq/GYxXljUEghNgAMxRJ/EKQG+yTyRukZ5Qj/7BxiVSKm3sCoo3923 2e86rXdBdg/YTPWKmXZNYTl8AIlOLuaAUNXQm9SVAoTIHXXrypakCNN0Kb89zL0fe0Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794591586; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=mUWTcnQgi6aZZHr0iyglv0TH0hI4+dmpxJoPESKuXJw=; b=DMbTioqJJs8XiBzUDhSn/MC5NPhSwTKA8BpY9YsGZ6Ja1kowrUVtW1sNMTqFOcRr50rd m6wsSirVi145N4L1GbVQeeqtsiic4RQfY8Q2x7i50GQZFCIZyZPNxtdRJRk99UvOeFl3n xVJmtaO7CtH3ioM3zKi/HsWzqO7uHUIlZgQlzvpJzeZi4baDKSmy6NntyPEt4jJMmB+dA 1mXiXn+fvPViboTjETzCb7SpjzEWcIKB3c4OolFgwD/91N9aocpcRvBOlmeqkFoYjIy2o 4NaIyev7KiDArWQm+VaR9kt4Jq/9IgPIPM3tEfwnH4r2wLdtfptKrFw8c3XCLkq0X0g== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=jY3PBS2K; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EEE6D606E679; Fri, 13 Nov 2026 17:39:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=jY3PBS2K Received: by smtp.kernel.org (Postfix) with ESMTPSA id A13561F000C5; Fri, 13 Nov 2026 17:39:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794591585; bh=mUWTcnQgi6aZZHr0iyglv0TH0hI4+dmpxJoPESKuXJw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=jY3PBS2KTrVxIC03G1+i35eTjK6IGMRgRP5KsC5X+J3uS/AtWUJXQgcaQCoNAd5mo Rcnky/XVyAAsq3PtZFxukxj9kAVwGg/TOd2a5JGC8M+31WqKD5uwdhk1qBhR7li544 Rq7fdfXfIf3f1mx2SVgd73DMWjQPeA8RNpfwkYVc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Bradley Morgan , Andrew Morton , Petr Mladek , Guenetr Roeck , Sashiko , Wang Jinchao , Wim Van Sebroeck , Sasha Levin Subject: [PATCH 6.12 632/670] panic: restore variable arguments to nmi_panic() Date: Fri, 13 Nov 2026 10:53:16 -0500 Message-ID: <20261113153833.206544247@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153811.177190860@linuxfoundation.org> References: <20261113153811.177190860@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bradley Morgan [ Upstream commit ed9e4c1ff15d5b935f467811541ca0aa6e49c5d0 ] nmi_panic() used to accept variable arguments until commit ebc41f20d77f ("panic: change nmi_panic from macro to function") flattened it to a final message string. vpanic() did not exist back then, so the function had to format through panic("%s", msg). Bring the variable arguments back and format with vpanic() directly. The next patch makes nmi_panic() try the panic_force_cpu= redirect before claiming panic_cpu. panic_try_force_cpu() needs to print the message but it is used also by panic() which accepts variable argument list. The string could be formatted only when a CPU gets assigned to process the redirection. Otherwise, there might be a race when writing to the `panic_force_buf`. No current caller passes a string with format specifiers. The closest one is hpwdt_pretimeout(), which builds panic_msg with hex_byte_pack() and has only two variants, both plain strings. But the new __printf() annotation on nmi_panic() would warn with -Wformat-security there because the buffer is passed directly as the format argument, so switch it to nmi_panic(regs, "%s", panic_msg). [pmladek@suse.com: changelog fix] Link: https://lore.kernel.org/arJxFybmtD7OBIcL@pathway.suse.cz Link: https://lore.kernel.org/20260916182957.7788-5-brads@mainlining.org Signed-off-by: Bradley Morgan Signed-off-by: Andrew Morton Suggested-by: Petr Mladek Reviewed-by: Petr Mladek Cc: Guenetr Roeck Cc: Sashiko Cc: Wang Jinchao Cc: Wim Van Sebroeck Cc: Signed-off-by: Sasha Levin --- drivers/watchdog/hpwdt.c | 2 +- include/linux/panic.h | 3 ++- kernel/panic.c | 10 ++++++++-- 3 files changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/watchdog/hpwdt.c b/drivers/watchdog/hpwdt.c index ba08189937ec6..32e9ac24e0d5f 100644 --- a/drivers/watchdog/hpwdt.c +++ b/drivers/watchdog/hpwdt.c @@ -198,7 +198,7 @@ static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs) } hex_byte_pack(panic_msg, nmistat); - nmi_panic(regs, panic_msg); + nmi_panic(regs, "%s", panic_msg); return NMI_HANDLED; } diff --git a/include/linux/panic.h b/include/linux/panic.h index baf7de33aa0e6..99c53d2792b1b 100644 --- a/include/linux/panic.h +++ b/include/linux/panic.h @@ -13,7 +13,8 @@ __printf(1, 2) void panic(const char *fmt, ...) __noreturn __cold; __printf(1, 0) void vpanic(const char *fmt, va_list args) __noreturn __cold; -void nmi_panic(struct pt_regs *regs, const char *msg); +__printf(2, 3) +void nmi_panic(struct pt_regs *regs, const char *fmt, ...); void check_panic_on_warn(const char *origin); extern void oops_enter(void); extern void oops_exit(void); diff --git a/kernel/panic.c b/kernel/panic.c index dce6197233161..0bc445155035a 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -246,13 +246,19 @@ EXPORT_SYMBOL(panic_on_other_cpu); * nmi_panic_self_stop() which can provide architecture dependent code such * as saving register state for crash dump. */ -void nmi_panic(struct pt_regs *regs, const char *msg) +void nmi_panic(struct pt_regs *regs, const char *fmt, ...) { + va_list args; + + va_start(args, fmt); + if (panic_try_start()) - panic("%s", msg); + vpanic(fmt, args); if (panic_on_other_cpu()) nmi_panic_self_stop(regs); + + va_end(args); } EXPORT_SYMBOL(nmi_panic); -- 2.53.0