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=1794047684; b=zXjikVpsDU9uVJdBm1xhIP1dVzZC4tHHQUcs91QRGynS8miS4CnRmXXpTcISqxaHKqol WR25FPK+WSi/4W6eKIea/L4PDQU9WGupYO7+UP+D8NykujTd729Ldme/cdibGLheoDfJ9 zenlqwmShElsyUHH6txJLYXZbtOM/scRn+/L97hAWcMVT3dn6o5RmefUhtWNTyhlpYGjB k0fgQeA9Tdj7nFreIJWIPZx9cGIfFmtKFWH8XoRRruVQtxqitirh22KUeUemv8T2IGMVz 4iZfM+aR/Jneu/T/BxPldfhD6/IfhOr8u9u+/Yo0XOh2XMs0AKDswqsEAX8tmip5XiQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794047684; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=pdXhV8lu0SNGH6q20AMc8lUV6oVFCMDBROIaxansjAo=; b=v9CCHuSnE8UU9tT2g9TVr8y67/t6O7cAO45gHNZPftvi8b4+cvRQA2GCw3SE0Nqa/7Zj nQz2apyhAQuNmWf++ijOX3X0H3sFdvQ7j85DSEiHJUW/GpQlWKKD204nzMBRywSlZc3yY IyKfeXuRb7FnHhLdmILBU7sCJEguP22f9mmrUphaTMxkCWA4VG0yYLgM0MQQRZcozqyz5 cfblI/sjcEzQkthhEuiVgvPRQ0E8TT0shqn5glKTF2BcykEPHcPuMEy8QqRWj4z42oRgO WImHx7cg4tb48avIR0HafIOqKppLKCD2AeZDhTKkMShp+iYkaoZOv7X5WSPP5+bXeMQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=a2CczKhT; 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 A05F1606A32D for ; Sat, 7 Nov 2026 10:34:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=a2CczKhT Received: by smtp.kernel.org (Postfix) with ESMTPSA id A923A1F0089F; Sat, 7 Nov 2026 10:34:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794047684; bh=pdXhV8lu0SNGH6q20AMc8lUV6oVFCMDBROIaxansjAo=; h=From:To:Cc:Subject:Date; b=a2CczKhTSRTGV5C2Xo9TQ+VgJ5tkS1rIxO1mijOGe7MNW8GH3caq6VHL8hTNmCQUn i+qCAxUsjhFMX4/y0Y4J5W0DsPm450SToLRSrP8FGKOFPdg2qHISY7M4DhApxRtAmA tDLN3s6PlUwRV55GizTQYl6e7UKpuCIIFwqWEnbhkp1R6NOi19nn7Hk7cWt7FKndE6 6L3poaCvfxwiewWGxrR3QlvOQe/x6uTiENUnjFpLRy1M6nMxXfbjvk1COgBbpERvo+ LJIsEH1aL321+mnptxHtakRytbpFov+KLjzAKZno1kKLxH7bEv+fEyJ4scFQ7P48jn lmXXjs4btqWtw== From: Sasha Levin To: brads@mainlining.org, akpm@linux-foundation.org, pmladek@suse.com, linux@roeck-us.net, sashiko-bot@kernel.org, wangjinchao600@gmail.com, wim@linux-watchdog.org Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] panic: restore variable arguments to nmi_panic()" failed to apply to 6.6-stable tree Date: Sat, 7 Nov 2026 05:34:42 -0500 Message-ID: <20261107053442-failed-6.6-ed9e4c1ff15d@kernel.org> X-Mailer: git-send-email 2.53.0 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-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x ed9e4c1ff15d5b935f467811541ca0aa6e49c5d0 # git commit -s git send-email --to '' --in-reply-to '20261107053442-failed-6.6-ed9e4c1ff15d@kernel.org' --subject-prefix 'PATCH 6.6.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From ed9e4c1ff15d5b935f467811541ca0aa6e49c5d0 Mon Sep 17 00:00:00 2001 From: Bradley Morgan Date: Wed, 16 Sep 2026 18:29:55 +0000 Subject: [PATCH] panic: restore variable arguments to nmi_panic() 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: --- 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 8af1fad2de0bd..78227d200afe4 100644 --- a/drivers/watchdog/hpwdt.c +++ b/drivers/watchdog/hpwdt.c @@ -199,7 +199,7 @@ 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 98dd7dfd27de7..17e61b61c45f8 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 7388eb81a1c47..e240ca06faab2 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -518,13 +518,19 @@ 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