From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.3]) (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 B1C413B14D8; Mon, 10 Aug 2026 09:47:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.3 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786355255; cv=none; b=uSyCGsnP/jXixr8Zf+phQL6wVoOdFiCSVSM/4ubujpwzAo5IfYHiQ5kQPr1xpcitNO0gsPm1VttPfcygW1ST8SWBK26lJZ7V1cTYocg/C7ZenrlWJnuQIsexq6vZlI/WruFLuHprXkKeOPRwSEc+CuvcFijsMgcbv/gKjGwTD/8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786355255; c=relaxed/simple; bh=I6s2kDHV5NNzxPQuLAUizQd6I7qHgorTT+1ejRTgt9A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=uKSAAfw+0SD69AuECvwpZZtJAROjA7HyqKwLSWWA6WEkCtYKzVfysH+BCp7qEu02PWzwIvHGtDyxWud9numBQwGU/x1E4oiBrYTqGGQM4DPgWwyXyfRQQfR7/Eesz41xm+1CCOAzwlKyQ0QKnlIwzeFWXccpcVvAufHrbTiTR+c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=buruPEEV; arc=none smtp.client-ip=220.197.31.3 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="buruPEEV" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=GW kY9gXXbMY/41WEf65U1kuHVxZQljY30qphw6Dd+ug=; b=buruPEEVXhP8NYvtX3 xhVLfSLhLGhBd19IamCvN9KazCpTadvRE4hUW3IRoVfqaGmNbnfweygfIO7UaOw0 RIzQ0QfVlRq0QWlPNfM2d2lGSNTWjux17sffbVvR8f9kQIzIlCENwiY48v2Ytqpa U+kqk9eMn6WSzdBRrcMk/4NmA= Received: from nec8-i7 (unknown []) by gzga-smtp-mtada-g0-3 (Coremail) with SMTP id _____wB3EocEnnlqAlAcOg--.9113S5; Mon, 10 Aug 2026 17:46:50 +0800 (CST) From: chenyuan_fl@163.com To: bpf@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Martin KaFai Lau , Song Liu , Yonghong Song , Jiri Olsa , Emil Tsalapatis , Ihor Solodrai , Yuan Chen Subject: [PATCH bpf-next v2 3/3] bpf, arena: check range_tree_set return in arena_free_pages and arena_free_worker Date: Mon, 10 Aug 2026 17:46:34 +0800 Message-ID: <20260810094634.2723213-4-chenyuan_fl@163.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260810094634.2723213-1-chenyuan_fl@163.com> References: <20260810094634.2723213-1-chenyuan_fl@163.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:_____wB3EocEnnlqAlAcOg--.9113S5 X-Coremail-Antispam: 1Uf129KBjvJXoW7CFWDtr1DAF1rJr4DGrykKrg_yoW8CF17pF 4DGa90yrs5Jw4xZrsxJrWkWF15G39Yqw48GrW8K3WfZ3s0v3sxtr48AF1UuFyUGrW8Xr4Y kF48Xw1FkrWDXFDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07j9pnPUUUUU= X-CM-SenderInfo: xfkh05pxdqswro6rljoofrz/xtbC5guiYGp5ngv+KwAA38 From: Yuan Chen arena_free_pages() and arena_free_worker() now handle range_tree_set() errors. arena_free_pages() aborts the free on error, and arena_free_worker() moves range_tree_set() before PTE clearing so that a failed tree update leaves the PTEs intact instead of freeing pages that the arena free tree does not track. Signed-off-by: Yuan Chen --- kernel/bpf/arena.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/kernel/bpf/arena.c b/kernel/bpf/arena.c index 555ee2531ef9..b374ebf2a4de 100644 --- a/kernel/bpf/arena.c +++ b/kernel/bpf/arena.c @@ -881,7 +881,12 @@ static void arena_free_pages(struct bpf_arena *arena, long uaddr, long page_cnt, if (ret) goto defer; - range_tree_set(&arena->rt, pgoff, page_cnt); + ret = range_tree_set(&arena->rt, pgoff, page_cnt); + if (ret) { + raw_res_spin_unlock_irqrestore(&arena->spinlock, flags); + bpf_map_memcg_exit(old_memcg, new_memcg); + return; + } init_llist_head(&free_pages); cdata.arena = arena; @@ -1004,11 +1009,18 @@ static void arena_free_worker(struct work_struct *work) kaddr = arena_vm_start + s->uaddr; pgoff = compute_pgoff(arena, s->uaddr); + /* + * Mark the range as free before clearing PTEs so that + * if the range tree update fails we leave the PTEs + * intact, avoiding an unrecoverable state where pages + * are freed but the arena free tree does not track them. + */ + if (range_tree_set(&arena->rt, pgoff, page_cnt)) + continue; + /* clear ptes and collect pages in free_pages llist */ apply_to_existing_page_range(&init_mm, kaddr, page_cnt << PAGE_SHIFT, apply_range_clear_cb, &cdata); - - range_tree_set(&arena->rt, pgoff, page_cnt); } raw_res_spin_unlock_irqrestore(&arena->spinlock, flags); -- 2.54.0