From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 CC1453EB0FD for ; Thu, 18 Jun 2026 13:07:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781788068; cv=none; b=c4PNpYjePerycDuvcJWdtW7mKPLE2h+2c+f4gfFvXpl5ffkHFm5DKXu1tVjiXlLihD9BKBTb47UdeYznTewt+VDbhxg5g45LZhGCKOCdV75FzGKv1Ot0hnsCycyVbR8T7Is737iDO8fItQC7s7ntsW3+LgOEET20uu7zStgIrGw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781788068; c=relaxed/simple; bh=hYE5Xcrz1mus+/4ZJzj86fcps2RafD1ZMa/1jh/fyTE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rMsg8ZuTqhjOoNZkf+Nn+HXaspQj/cRYAaD2onlAHNd2B+5NvFv2n+g5DC/fUsLk1zClICE+9yVLbKftssVfSWSC4jXqSVesBmPn2dSScPJpDtZN6EP6QzvZPhnBK+YPQvJ0taguKdbrKQzYrSSdPTT2yIxlgGPmpJC5B69rG7Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PYvWsBhA; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="PYvWsBhA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D703D1F00A3D; Thu, 18 Jun 2026 13:07:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781788067; bh=tDER9sCYxQ81+/oFf6dg7osjFmwW/E/0DyKWfr5TzhA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=PYvWsBhAi4wlJLEqQY5RAofNI4+30/TM40Oo0MmRGcXgrE9l0cTbMsPzmGNcedjGz boZMmBD0Mso6kblOM1Y1++TE9KX2l9YjofTb8e5hnG7/9Ut1Ciqi+ntCGre1l1mbQ+ dYjtF68PixSlV30nZ/oItewycKuMpk/sj+NEl8uOS7gKwbM85HZamq2oyITIYpQtzF JH+kuXNKgpe8PGtp0Td1tKepbsD32mRyLzLmlRTCEP4fwfzWl7fn6PVz4xlq5vCpIQ EQ/ZYWeBmfsRPc2Qk0X+OzcgypRBbjYZ3JMxOH4gjo5QH/V/56M3SqnAF/Wgn/T3r2 03yu4AQWO1ezA== From: Sasha Levin To: stable@vger.kernel.org Cc: Helen Koike , syzbot+b8ca586b9fc235f0c0df@syzkaller.appspotmail.com, Thomas Gleixner , Sasha Levin Subject: [PATCH 6.12.y 2/2] debugobjects: Do not fill_pool() if pi_blocked_on Date: Thu, 18 Jun 2026 09:07:44 -0400 Message-ID: <20260618130744.699242-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260618130744.699242-1-sashal@kernel.org> References: <2026061610-brunette-clasp-5eb6@gregkh> <20260618130744.699242-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Helen Koike [ Upstream commit 5f41161059fd0f1bbf18c90f3180e38cc45a14eb ] On RT enabled kernels, fill_pool() ends up calling rtlock_lock(), which asserts if current::pi_blocked_on is set, because a task can obviously only block on one lock as otherwise the priority inheritenace chain gets corrupted. Prevent this by expanding the conditional to take current::pi_blocked_on into account. Fixes: 4bedcc28469a ("debugobjects: Make them PREEMPT_RT aware") Reported-by: syzbot+b8ca586b9fc235f0c0df@syzkaller.appspotmail.com Signed-off-by: Helen Koike Signed-off-by: Thomas Gleixner Link: https://patch.msgid.link/20260511215359.3351259-1-koike@igalia.com Closes: https://syzkaller.appspot.com/bug?extid=b8ca586b9fc235f0c0df Signed-off-by: Sasha Levin --- lib/debugobjects.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/lib/debugobjects.c b/lib/debugobjects.c index d69721bb78b797..dfb859995f29db 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -596,15 +596,25 @@ static struct debug_obj *lookup_object_or_alloc(void *addr, struct debug_bucket return NULL; } +static inline bool debug_objects_is_pi_blocked_on(void) +{ +#ifdef CONFIG_RT_MUTEXES + return current->pi_blocked_on != NULL; +#else + return false; +#endif +} + static void debug_objects_fill_pool(void) { /* * On RT enabled kernels the pool refill must happen in preemptible - * context -- for !RT kernels we rely on the fact that spinlock_t and - * raw_spinlock_t are basically the same type and this lock-type - * inversion works just fine. + * context and not enqueued on an rt_mutex -- for !RT kernels we rely + * on the fact that spinlock_t and raw_spinlock_t are basically the + * same type and this lock-type inversion works just fine. */ - if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible() || system_state < SYSTEM_SCHEDULING) { + if (!IS_ENABLED(CONFIG_PREEMPT_RT) || system_state < SYSTEM_SCHEDULING || + (preemptible() && !debug_objects_is_pi_blocked_on())) { /* * Annotate away the spinlock_t inside raw_spinlock_t warning * by temporarily raising the wait-type to WAIT_SLEEP, matching -- 2.53.0