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=1794061558; b=e3zqpvV1vj8x1u0vU3X28MmjiA9rAwgXTn1blps02tvARrMx22XHeHFQfYVStdeG3JU1 PbBH6cJ3IcQpGSpGhm6yHyxriC0hUkTHv7lX3zxAYORVoeqOU3Naflo/VOY8VROYBrRrQ i8BthgcWhD+OcCqdjoI7UDWSqs1hTO16NJWisxSegfX8BaE2UXSatisCLSGJQfSTq/gju RB3gLXrR7v8Fp6RNG5DVCX49A+6nv+T781EVo3flku+RZyqEPr/JWiH3LbsfLPxmwnVcW EhSSgcSLUvU70JHU7OLY5STImiBlw18ZWA7Vz5KBpSq1Rt+5b1lk4fMjNt3kJ+iJKhw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794061558; 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=gIOUAa5DNlm8wfJh2d1fOKSfvgNe7h8u9TIMfdNObeU=; b=OyxnAvsvfHIRVcz+TWgqAfc/9HnhsM4m7Wo5f33QfZandWILjelm0qup/z6mXouqgXOb QOQUJx/0VjGzAbd3oGLiOViIGKMZF0kvAbSzmWBOhPuiuDm1hT7qWr1Q+dSl6YM/PL9Xw 7wPbj3ND6d8J6noBqSUamS+kDreZEu9zKpjgh9rFEFWkIa62XCOm9Fw9u0NClehwasd9k ved2fvGj/LeD2uBjxwxA2SnhGLoGm326ieyj+pCeF2/93ikjL4Fwh/3+cNEk8tKPZm8B/ PivDOErkk2kGcxCOCF9xK9ZuRT/T6RN9kfBocr7sgPbJ10aKpeUdXxuViOnowFnmWeA== 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=sEm5HduB; 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 E75B6606A32F; Sat, 7 Nov 2026 14:25:57 +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=sEm5HduB Received: by smtp.kernel.org (Postfix) with ESMTPSA id 908781F008A1; Sat, 7 Nov 2026 14:25:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794061557; bh=gIOUAa5DNlm8wfJh2d1fOKSfvgNe7h8u9TIMfdNObeU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=sEm5HduBXk7GN9seUjT2zY6Ok4CsocAF3x5JFPFJl3tI5nRooLJL4ZMbgSNFEcYen d15iosIRtI3u13aeTbILOjZOIj8ihiaJwlonqQMmQ+VyfNrMHJ8UqKatTEg83n9afP wT0Nr4IwspcPj3ZjVDIlYXS/GIdI0WMK8fV2vi68= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Richard Patel , Thomas Gleixner Subject: [PATCH 6.12 0639/1536] genirq: Move interrupt thread exit_work object to irqaction Date: Sat, 7 Nov 2026 08:44:15 -0500 Message-ID: <20261107135015.479803595@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134957.653319350@linuxfoundation.org> References: <20261107134957.653319350@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: Richard Patel commit 89a9e003a2ef73f67dff03dfd59e0a5474b56b0b upstream. irq_thread() registers irq_thread_dtor() as exit task_work using a stack-allocated callback_head. On normal interrupt thread exit, this work gets cancelled and never runs. On x86, an abnormal interrupt thread exit (e.g. handler oops) discards the stack, including the callback_head, while that callback_head is still pending. By the time exit_task_work() runs, the stack memory formerly backing callback_head is already clobbered. irq_thread() <-- on_exit_work allocated ** IRQ handler faults ** oops_end() rewind_stack_and_make_dead() <-- on_exit_work freed make_task_dead() do_exit(SIGSEGV) ... exit_shm() <-- on_exit_work clobbered ... exit_task_work() <-- stack use-after-free exit_shm()+0x30 <-- wild jump to return addr Thus, a benign threaded IRQ oops (e.g. a NULL pointer deref) is turned into a wild jump. This is caught by kernel IBT: ** first fault ** Oops: general protection fault, kernel NULL pointer dereference 0x3c0: 0000 [#1] SMP NOPTI ... ** second fault ** Missing ENDBR: exit_shm+0x30/0x1c0 kernel BUG at arch/x86/kernel/cet.c:133! ... ? task_work_run+0x5c/0x90 ? do_exit+0x209/0x460 ? rewind_stack_and_make_dead+0x16/0x20 ... note: irq/165-AudioDS[1427] exited with irqs disabled Fixing recursive fault but reboot is needed! Fix this by storing the callback_head in struct irqaction. The irqaction is only freed once irq_thread_dtor() finishes. Fixes: 2deb4be28077 ("x86/dumpstack: When OOPSing, rewind the stack before do_exit()") Signed-off-by: Richard Patel Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20261009145842.1616117-3-ripatel@wii.dev Signed-off-by: Greg Kroah-Hartman --- include/linux/interrupt.h | 2 ++ kernel/irq/manage.c | 9 ++++----- 2 files changed, 6 insertions(+), 5 deletions(-) --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -118,6 +118,7 @@ typedef irqreturn_t (*irq_handler_t)(int * @thread_flags: flags related to @thread * @thread_mask: bitmask for keeping track of @thread activity * @dir: pointer to the proc/irq/NN/name entry + * @thread_dtor: task_work for @thread irregular exit cleanup */ struct irqaction { irq_handler_t handler; @@ -133,6 +134,7 @@ struct irqaction { unsigned long thread_mask; const char *name; struct proc_dir_entry *dir; + struct callback_head thread_dtor; } ____cacheline_internodealigned_in_smp; extern irqreturn_t no_action(int cpl, void *dev_id); --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -1255,9 +1255,9 @@ static void __irq_thread_dtor(struct irq irq_finalize_oneshot(desc, action); } -static void irq_thread_dtor(struct callback_head *unused) +static void irq_thread_dtor(struct callback_head *work) { - struct irqaction *action = kthread_data(current); + struct irqaction *action = container_of(work, struct irqaction, thread_dtor); __irq_thread_dtor(action); clear_and_wake_up_bit(IRQTF_EXIT_WORK, &action->thread_flags); @@ -1305,7 +1305,6 @@ static void wake_up_and_wait_for_irq_thr */ static int irq_thread(void *data) { - struct callback_head on_exit_work; struct irqaction *action = data; struct irq_desc *desc = irq_to_desc(action->irq); irqreturn_t (*handler_fn)(struct irq_desc *desc, @@ -1322,8 +1321,8 @@ static int irq_thread(void *data) handler_fn = irq_thread_fn; set_bit(IRQTF_EXIT_WORK, &action->thread_flags); - init_task_work(&on_exit_work, irq_thread_dtor); - task_work_add(current, &on_exit_work, TWA_NONE); + init_task_work(&action->thread_dtor, irq_thread_dtor); + task_work_add(current, &action->thread_dtor, TWA_NONE); while (!irq_wait_for_interrupt(desc, action)) { irqreturn_t action_ret;