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=1794585984; b=X5i8H5/bYe0Q9EYh8UMj35mRIfEuBmyOZ8oyHBQkCP+UAbDhfvZxuO3AMTclQJv2+3y3 QFcJsu6cmOKj8tASI8v0M+77YE05bp6Lq9/bAEYcYS5fpU7IdgAq5QB5FjnsWdShrh3gO FXuagi/z+x2YFKEz9QURMEA+cfirbbWX59xgn2gI6ZX/6z1CXkS7wzV+PUP9N5s7OOaSe 4zJuYUpcUg+cLIgihOCkO2CvaXisRgeEk0GebqFMsxYbBMuLmnR52TBpfUAjXLRmyS+o6 ae+qQz+qACuOwlvItDwG34fOvMN7Ou0OpH2jH0gy+Ch5jrof/51P8Y18jzeKfXpihkg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794585984; 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=F7Uv95lRIeLStSQeOSoyMGEVIsUxKmyGVvUd9yxu6BE=; b=KDyAX9yyEr6O7hKI2hwhmrjtOGH5VGZbOnEA0oZh1VB2RRzTusS926vphQvAnzGGpiEL c44Oq/bLhyjkRcR8kmIacmQ1MrI/8KQ2aqTc1C3ALvEVigN3kvhSSkByMkfdaQyBlQt4c keZ+FV0yC5SZ/W5wsD1OCGo7ZH469N+bUH0L2MpogovKCqzK0T8MMLwai3mffNla5Wy4T UaRDma+1J8twrAv2cmfd1DgpkDFNNU1XyKUMnKuLK8LaQhoe24O30GWt2n4YRTnk9Z3Ot nrxbeWOOhpLBeajwNVJ40n63WjTTcZYlwN8Gb1IzhQLOD9HnBBgHldCFMQilS8t5vxQ== 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=UFQo4WJh; 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 9AB156072317; Fri, 13 Nov 2026 16:06:24 +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=UFQo4WJh Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3C6091F000C4; Fri, 13 Nov 2026 16:06:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794585984; bh=F7Uv95lRIeLStSQeOSoyMGEVIsUxKmyGVvUd9yxu6BE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=UFQo4WJhg6oKutqawRG2qy2DjNfA97vh6yR0Vmxw6PwwcPpxuIygXAsMX8kb3mSoj fyxld4an9nTgUkqTjq0sASOxHf3Sz94taPtvf8y9mToGGILFY+XdwLta25Jz6zlGgI Omul/Uwt484AH/KtSaWQ7kN3xrLBdp6DyAP4lzaE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Darrick J. Wong" , Christoph Hellwig , Carlos Maiolino , Sasha Levin Subject: [PATCH 6.18 029/686] xfs: improve dirent bounds checking in scrub and repair Date: Fri, 13 Nov 2026 10:42:42 -0500 Message-ID: <20261113153821.972554974@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153820.902362109@linuxfoundation.org> References: <20261113153820.902362109@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Darrick J. Wong [ Upstream commit 5d470234d04dae6fe2ca2cf4b9ef277b78c7e05a ] LOLLM complains that we don't do enough bounds checking of the directory entries in directory blocks when we're looking for errors or trying to salvage entries. Let's improve that with more detailed checks. Cc: stable@vger.kernel.org # v4.16 Fixes: ce92d29ddf9908 ("xfs: directory scrubber must walk through data block to offset") Signed-off-by: Darrick J. Wong Assisted-by: LOLLM # finding obvious bugs Reviewed-by: Christoph Hellwig Signed-off-by: Carlos Maiolino Signed-off-by: Sasha Levin --- fs/xfs/scrub/dir.c | 68 +++++++++++++++++++++++++++++++++------ fs/xfs/scrub/dir_repair.c | 37 ++++++++++++++++++--- 2 files changed, 91 insertions(+), 14 deletions(-) diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c index 2f73baee0f0b4..495fdf3b519ae 100644 --- a/fs/xfs/scrub/dir.c +++ b/fs/xfs/scrub/dir.c @@ -323,11 +323,24 @@ xchk_dir_check_unused( struct xchk_da_btree *ds, struct xfs_buf *bp, unsigned int iter_off, - unsigned int end) + unsigned int end, + xfs_dablk_t rec_bno) { struct xfs_dir2_data_unused *dup = bp->b_addr + iter_off; + unsigned int advance; + + if (iter_off + sizeof(*dup) > end) { + xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno); + return -1; + } + + advance = xfs_dir2_data_unusedsize(be16_to_cpu(dup->length)); + if (!advance || iter_off + advance > end) { + xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno); + return -1; + } - return be16_to_cpu(dup->length); + return advance; } /* @@ -341,15 +354,31 @@ xchk_dir_check_entry( struct xfs_buf *bp, unsigned int iter_off, unsigned int end, - struct xfs_dir2_data_entry *dent) + struct xfs_dir2_data_entry *dent, + xfs_dablk_t rec_bno) { struct xfs_dir2_data_entry *dep = bp->b_addr + iter_off; struct xfs_mount *mp = ds->state->mp; + unsigned int advance; + + /* must have namelen */ + advance = offsetof(typeof(*dep), name); + if (iter_off + advance >= end) { + xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno); + return -1; + } + + /* Don't walk off the end of the block. */ + advance = xfs_dir2_data_entsize(mp, dep->namelen); + if (!advance || iter_off + advance > end) { + xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno); + return -1; + } if (dep == dent) return 0; - return xfs_dir2_data_entsize(mp, dep->namelen); + return advance; } /* Scrub a directory btree record. */ @@ -377,6 +406,7 @@ xchk_dir_rec( xfs_dahash_t hash; struct xfs_dir3_icleaf_hdr hdr; unsigned int tag; + bool foundit = false; int error; ASSERT(blk->magic == XFS_DIR2_LEAF1_MAGIC || @@ -421,33 +451,44 @@ xchk_dir_rec( dent = bp->b_addr + off; /* Make sure we got a real directory entry. */ - iter_off = geo->data_entry_offset; end = xfs_dir3_data_end_offset(geo, bp->b_addr); if (!end) { xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno); goto out_relse; } - for (;;) { + iter_off = geo->data_entry_offset; + while (iter_off < end) { struct xfs_dir2_data_unused *dup = bp->b_addr + iter_off; int advance; - if (iter_off >= end) { + /* must have freetag */ + advance = offsetof(typeof(*dup), length); + if (iter_off + advance >= end) { xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno); goto out_relse; } if (dup->freetag == cpu_to_be16(XFS_DIR2_DATA_FREE_TAG)) - advance = xchk_dir_check_unused(ds, bp, iter_off, end); + advance = xchk_dir_check_unused(ds, bp, iter_off, end, + rec_bno); else advance = xchk_dir_check_entry(ds, bp, iter_off, end, - dent); + dent, rec_bno); if (advance < 0) goto out_relse; - if (!advance) + if (!advance) { + foundit = true; break; + } iter_off += advance; } + /* Hash tree must point to the exact dirent */ + if (!foundit) { + xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno); + goto out_relse; + } + /* Retrieve the entry, sanity check it, and compare hashes. */ ino = be64_to_cpu(dent->inumber); hash = be32_to_cpu(ent->hashval); @@ -459,6 +500,13 @@ xchk_dir_rec( goto out_relse; } + /* Name must not overflow end of block */ + if ((char *)dent->name + dent->namelen > + (char *)bp->b_addr + BBTOB(bp->b_length)) { + xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno); + goto out_relse; + } + /* Does the directory hash match? */ dname.name = dent->name; dname.len = dent->namelen; diff --git a/fs/xfs/scrub/dir_repair.c b/fs/xfs/scrub/dir_repair.c index f8e88b638c43d..c7fd39fd83a48 100644 --- a/fs/xfs/scrub/dir_repair.c +++ b/fs/xfs/scrub/dir_repair.c @@ -473,8 +473,16 @@ xrep_dir_recover_unused( unsigned int end) { struct xfs_dir2_data_unused *dup = bp->b_addr + offset; + unsigned int advance; + + if (offset + sizeof(*dup) > end) + return 0; + + advance = xfs_dir2_data_unusedsize(be16_to_cpu(dup->length)); + if (!advance || offset + advance > end) + return 0; - return be16_to_cpu(dup->length); + return advance; } /* @@ -492,11 +500,14 @@ xrep_dir_recover_entry( unsigned int advance; int error; + /* must have namelen */ + advance = offsetof(typeof(*dep), name); + if (offset + advance >= end) + return 0; + /* Don't walk off the end of the block. */ advance = xfs_dir2_data_entsize(rd->sc->mp, dep->namelen); - if (!advance) - return 0; - if (offset + advance > end) + if (!advance || offset + advance > end) return 0; /* Ok, let's save this entry. */ @@ -534,6 +545,11 @@ xrep_dir_recover_data( if (xchk_should_terminate(rd->sc, &error)) return error; + /* must have freetag */ + advance = offsetof(typeof(*dup), length); + if (offset + advance >= end) + break; + if (dup->freetag == cpu_to_be16(XFS_DIR2_DATA_FREE_TAG)) advance = xrep_dir_recover_unused(bp, offset, end); else @@ -565,6 +581,19 @@ xrep_dir_recover_sf( hdr = ifp->if_data; end = (unsigned char *)ifp->if_data + ifp->if_bytes; + /* sf header must be big enough for count/i8count */ + if (!hdr || ifp->if_bytes < 2) + return 0; + + /* and large enough for the parent inumber */ + if (hdr->i8count) { + if (ifp->if_bytes < offsetof(struct xfs_dir2_sf_hdr, parent[8])) + return 0; + } else { + if (ifp->if_bytes < offsetof(struct xfs_dir2_sf_hdr, parent[4])) + return 0; + } + ino = xfs_dir2_sf_get_parent_ino(hdr); trace_xrep_dir_salvaged_parent(rd->sc->ip, ino); -- 2.53.0