From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 204EE1EA7DB for ; Thu, 1 May 2025 14:14:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746108876; cv=none; b=a9BX3vk9OeLf5YExod8WxeWZoMyNRR6zAoCEGwDQWSebdyIyIXLFOyEqELydV10DKGP3Nv8bQpXeXF5kgv/LbpcMwE60/n6oP1S6fuYe/hPNjnHfBTOv261euGDtGrki87so0P62qK9QsshBU4KUCBOXKZpA29Wv7TjigHiQ27o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746108876; c=relaxed/simple; bh=ff0t4sFBbc7Ev7YOvQTQVVeeUdaJwOvAAs3P9yca3fQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=klUbGyjjusxu564/3YQwGxV5Sq8UdyigHUCRLbkC3svTW5ohQGvmA5og4Mw3lA6baRfXkzhowv/pr0RDckkGQRW0dvsz7EOu+V0/eo2NDZ8GpFe4Fx/ERav61LSVceKOAu+hrKH7RAxM74U6hh/WuXy3uetIZsKTPvVKEyavQjE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=KQAIpvVB; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="KQAIpvVB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A202AC4CEE3; Thu, 1 May 2025 14:14:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1746108876; bh=ff0t4sFBbc7Ev7YOvQTQVVeeUdaJwOvAAs3P9yca3fQ=; h=From:To:Cc:Subject:Date:Reply-to:From; b=KQAIpvVB6qR9HTZS9GJPcr5Kr9OoQHF9oY2oFKhlBvixmbVU2Z1ApPMUbi6DGzCEP BOCXANvfL6+51PWhBkJk4ooWtcqSfGJoudLy1CqbrHLMGMsLly/lVjlSkhamQ4JaWm LAlG0C9L9G+aZOnbkMbABPVzVV8At5nvdOCYtago= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2022-49810: netfs: Fix missing xas_retry() calls in xarray iteration Date: Thu, 1 May 2025 16:10:00 +0200 Message-ID: <2025050129-CVE-2022-49810-e637@gregkh> X-Mailer: git-send-email 2.49.0 Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Reply-to: , X-Developer-Signature: v=1; a=openpgp-sha256; l=3222; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=Vbc1n1HapYsIhn20yiZ68UBuXFrsFhY/ahurK+Fh1Uk=; b=owGbwMvMwCRo6H6F97bub03G02pJDBnCDTP15A7+3vN1r/e/vQlnP21pK2neWujNLKNRnzc9+ SPrVPagjlgWBkEmBlkxRZYv23iO7q84pOhlaHsaZg4rE8gQBi5OAZjImy8M85R+nNwxnZXz+xeN jMOGTxiefVX3/sqw4Pqnm1fnSm3P/LWfuWTdfMV+Jhm5IgA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: netfs: Fix missing xas_retry() calls in xarray iteration netfslib has a number of places in which it performs iteration of an xarray whilst being under the RCU read lock. It *should* call xas_retry() as the first thing inside of the loop and do "continue" if it returns true in case the xarray walker passed out a special value indicating that the walk needs to be redone from the root[*]. Fix this by adding the missing retry checks. [*] I wonder if this should be done inside xas_find(), xas_next_node() and suchlike, but I'm told that's not an simple change to effect. This can cause an oops like that below. Note the faulting address - this is an internal value (|0x2) returned from xarray. BUG: kernel NULL pointer dereference, address: 0000000000000402 ... RIP: 0010:netfs_rreq_unlock+0xef/0x380 [netfs] ... Call Trace: netfs_rreq_assess+0xa6/0x240 [netfs] netfs_readpage+0x173/0x3b0 [netfs] ? init_wait_var_entry+0x50/0x50 filemap_read_page+0x33/0xf0 filemap_get_pages+0x2f2/0x3f0 filemap_read+0xaa/0x320 ? do_filp_open+0xb2/0x150 ? rmqueue+0x3be/0xe10 ceph_read_iter+0x1fe/0x680 [ceph] ? new_sync_read+0x115/0x1a0 new_sync_read+0x115/0x1a0 vfs_read+0xf3/0x180 ksys_read+0x5f/0xe0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae Changes: ======== ver #2) - Changed an unsigned int to a size_t to reduce the likelihood of an overflow as per Willy's suggestion. - Added an additional patch to fix the maths. The Linux kernel CVE team has assigned CVE-2022-49810 to this issue. Affected and fixed versions =========================== Issue introduced in 5.13 with commit 3d3c95046742e4eebaa4b891b0b01cbbed94ebbd and fixed in 6.0.10 with commit b2cc07a76f1eb12de3b22caf5fdbf856a7bef16d Issue introduced in 5.13 with commit 3d3c95046742e4eebaa4b891b0b01cbbed94ebbd and fixed in 6.1 with commit 7e043a80b5dae5c2d2cf84031501de7827fd6c00 Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2022-49810 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: fs/netfs/buffered_read.c fs/netfs/io.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/b2cc07a76f1eb12de3b22caf5fdbf856a7bef16d https://git.kernel.org/stable/c/7e043a80b5dae5c2d2cf84031501de7827fd6c00