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authorDave Chinner <dchinner@redhat.com>2018-06-06 05:42:13 +0300
committerDarrick J. Wong <darrick.wong@oracle.com>2018-06-06 18:12:00 +0300
commit9e6c08d4a8fc21fc496bf4543e5b2360fc610866 (patch)
tree4327a5e43e0ecb12a4dbb5afbed86ad487d1ba34 /fs/xfs
parent29cad0b3edaffb65f78f61b63cb0c43f87f98865 (diff)
downloadlinux-9e6c08d4a8fc21fc496bf4543e5b2360fc610866.tar.xz
xfs: validate btree records on retrieval
So we don't check the validity of records as we walk the btree. When there are corrupt records in the free space btree (e.g. zero startblock/length or beyond EOAG) we just blindly use it and things go bad from there. That leads to assert failures on debug kernels like this: XFS: Assertion failed: fs_is_ok, file: fs/xfs/libxfs/xfs_alloc.c, line: 450 .... Call Trace: xfs_alloc_fixup_trees+0x368/0x5c0 xfs_alloc_ag_vextent_near+0x79a/0xe20 xfs_alloc_ag_vextent+0x1d3/0x330 xfs_alloc_vextent+0x5e9/0x870 Or crashes like this: XFS (loop0): xfs_buf_find: daddr 0x7fb28 out of range, EOFS 0x8000 ..... BUG: unable to handle kernel NULL pointer dereference at 00000000000000c8 .... Call Trace: xfs_bmap_add_extent_hole_real+0x67d/0x930 xfs_bmapi_write+0x934/0xc90 xfs_da_grow_inode_int+0x27e/0x2f0 xfs_dir2_grow_inode+0x55/0x130 xfs_dir2_sf_to_block+0x94/0x5d0 xfs_dir2_sf_addname+0xd0/0x590 xfs_dir_createname+0x168/0x1a0 xfs_rename+0x658/0x9b0 By checking that free space records pulled from the trees are within the valid range, we catch many of these corruptions before they can do damage. This is a generic btree record checking deficiency. We need to validate the records we fetch from all the different btrees before we use them to catch corruptions like this. This patch results in a corrupt record emitting an error message and returning -EFSCORRUPTED, and the higher layers catch that and abort: XFS (loop0): Size Freespace BTree record corruption in AG 0 detected! XFS (loop0): start block 0x0 block count 0x0 XFS (loop0): Internal error xfs_trans_cancel at line 1012 of file fs/xfs/xfs_trans.c. Caller xfs_create+0x42a/0x670 ..... Call Trace: dump_stack+0x85/0xcb xfs_trans_cancel+0x19f/0x1c0 xfs_create+0x42a/0x670 xfs_generic_create+0x1f6/0x2c0 vfs_create+0xf9/0x180 do_mknodat+0x1f9/0x210 do_syscall_64+0x5a/0x180 entry_SYSCALL_64_after_hwframe+0x49/0xbe ..... XFS (loop0): xfs_do_force_shutdown(0x8) called from line 1013 of file fs/xfs/xfs_trans.c. Return address = ffffffff81500868 XFS (loop0): Corruption of in-memory data detected. Shutting down filesystem Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs/xfs')
-rw-r--r--fs/xfs/libxfs/xfs_alloc.c22
-rw-r--r--fs/xfs/libxfs/xfs_ialloc.c31
-rw-r--r--fs/xfs/libxfs/xfs_refcount.c47
-rw-r--r--fs/xfs/libxfs/xfs_rmap.c41
4 files changed, 132 insertions, 9 deletions
diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index 0214a77808d0..1bd405eec285 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -227,6 +227,8 @@ xfs_alloc_get_rec(
xfs_extlen_t *len, /* output: length of extent */
int *stat) /* output: success/failure */
{
+ struct xfs_mount *mp = cur->bc_mp;
+ xfs_agnumber_t agno = cur->bc_private.a.agno;
union xfs_btree_rec *rec;
int error;
@@ -234,12 +236,28 @@ xfs_alloc_get_rec(
if (error || !(*stat))
return error;
if (rec->alloc.ar_blockcount == 0)
- return -EFSCORRUPTED;
+ goto out_bad_rec;
*bno = be32_to_cpu(rec->alloc.ar_startblock);
*len = be32_to_cpu(rec->alloc.ar_blockcount);
- return error;
+ /* check for valid extent range, including overflow */
+ if (!xfs_verify_agbno(mp, agno, *bno))
+ goto out_bad_rec;
+ if (*bno > *bno + *len)
+ goto out_bad_rec;
+ if (!xfs_verify_agbno(mp, agno, *bno + *len - 1))
+ goto out_bad_rec;
+
+ return 0;
+
+out_bad_rec:
+ xfs_warn(mp,
+ "%s Freespace BTree record corruption in AG %d detected!",
+ cur->bc_btnum == XFS_BTNUM_BNO ? "Block" : "Size", agno);
+ xfs_warn(mp,
+ "start block 0x%x block count 0x%x", *bno, *len);
+ return -EFSCORRUPTED;
}
/*
diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c
index 48296adbb0fb..ad53aa5e4ea7 100644
--- a/fs/xfs/libxfs/xfs_ialloc.c
+++ b/fs/xfs/libxfs/xfs_ialloc.c
@@ -133,16 +133,45 @@ xfs_inobt_get_rec(
struct xfs_inobt_rec_incore *irec,
int *stat)
{
+ struct xfs_mount *mp = cur->bc_mp;
+ xfs_agnumber_t agno = cur->bc_private.a.agno;
union xfs_btree_rec *rec;
int error;
+ uint64_t realfree;
error = xfs_btree_get_rec(cur, &rec, stat);
if (error || *stat == 0)
return error;
- xfs_inobt_btrec_to_irec(cur->bc_mp, rec, irec);
+ xfs_inobt_btrec_to_irec(mp, rec, irec);
+
+ if (!xfs_verify_agino(mp, agno, irec->ir_startino))
+ goto out_bad_rec;
+ if (irec->ir_count < XFS_INODES_PER_HOLEMASK_BIT ||
+ irec->ir_count > XFS_INODES_PER_CHUNK)
+ goto out_bad_rec;
+ if (irec->ir_freecount > XFS_INODES_PER_CHUNK)
+ goto out_bad_rec;
+
+ /* if there are no holes, return the first available offset */
+ if (!xfs_inobt_issparse(irec->ir_holemask))
+ realfree = irec->ir_free;
+ else
+ realfree = irec->ir_free & xfs_inobt_irec_to_allocmask(irec);
+ if (hweight64(realfree) != irec->ir_freecount)
+ goto out_bad_rec;
return 0;
+
+out_bad_rec:
+ xfs_warn(mp,
+ "%s Inode BTree record corruption in AG %d detected!",
+ cur->bc_btnum == XFS_BTNUM_INO ? "Used" : "Free", agno);
+ xfs_warn(mp,
+"start inode 0x%x, count 0x%x, free 0x%x freemask 0x%llx, holemask 0x%x",
+ irec->ir_startino, irec->ir_count, irec->ir_freecount,
+ irec->ir_free, irec->ir_holemask);
+ return -EFSCORRUPTED;
}
/*
diff --git a/fs/xfs/libxfs/xfs_refcount.c b/fs/xfs/libxfs/xfs_refcount.c
index 418d53295893..e8ef951887ef 100644
--- a/fs/xfs/libxfs/xfs_refcount.c
+++ b/fs/xfs/libxfs/xfs_refcount.c
@@ -125,16 +125,53 @@ xfs_refcount_get_rec(
struct xfs_refcount_irec *irec,
int *stat)
{
+ struct xfs_mount *mp = cur->bc_mp;
+ xfs_agnumber_t agno = cur->bc_private.a.agno;
union xfs_btree_rec *rec;
int error;
+ xfs_agblock_t realstart;
error = xfs_btree_get_rec(cur, &rec, stat);
- if (!error && *stat == 1) {
- xfs_refcount_btrec_to_irec(rec, irec);
- trace_xfs_refcount_get(cur->bc_mp, cur->bc_private.a.agno,
- irec);
+ if (error || !*stat)
+ return error;
+
+ xfs_refcount_btrec_to_irec(rec, irec);
+
+ agno = cur->bc_private.a.agno;
+ if (irec->rc_blockcount == 0 || irec->rc_blockcount > MAXREFCEXTLEN)
+ goto out_bad_rec;
+
+ /* handle special COW-staging state */
+ realstart = irec->rc_startblock;
+ if (realstart & XFS_REFC_COW_START) {
+ if (irec->rc_refcount != 1)
+ goto out_bad_rec;
+ realstart &= ~XFS_REFC_COW_START;
+ } else if (irec->rc_refcount < 2) {
+ goto out_bad_rec;
}
- return error;
+
+ /* check for valid extent range, including overflow */
+ if (!xfs_verify_agbno(mp, agno, realstart))
+ goto out_bad_rec;
+ if (realstart > realstart + irec->rc_blockcount)
+ goto out_bad_rec;
+ if (!xfs_verify_agbno(mp, agno, realstart + irec->rc_blockcount - 1))
+ goto out_bad_rec;
+
+ if (irec->rc_refcount == 0 || irec->rc_refcount > MAXREFCOUNT)
+ goto out_bad_rec;
+
+ trace_xfs_refcount_get(cur->bc_mp, cur->bc_private.a.agno, irec);
+ return 0;
+
+out_bad_rec:
+ xfs_warn(mp,
+ "Refcount BTree record corruption in AG %d detected!", agno);
+ xfs_warn(mp,
+ "Start block 0x%x, block count 0x%x, references 0x%x",
+ irec->rc_startblock, irec->rc_blockcount, irec->rc_refcount);
+ return -EFSCORRUPTED;
}
/*
diff --git a/fs/xfs/libxfs/xfs_rmap.c b/fs/xfs/libxfs/xfs_rmap.c
index c0644f1be8a8..220cc72754e4 100644
--- a/fs/xfs/libxfs/xfs_rmap.c
+++ b/fs/xfs/libxfs/xfs_rmap.c
@@ -39,6 +39,7 @@
#include "xfs_extent_busy.h"
#include "xfs_bmap.h"
#include "xfs_inode.h"
+#include "xfs_ialloc.h"
/*
* Lookup the first record less than or equal to [bno, len, owner, offset]
@@ -203,6 +204,8 @@ xfs_rmap_get_rec(
struct xfs_rmap_irec *irec,
int *stat)
{
+ struct xfs_mount *mp = cur->bc_mp;
+ xfs_agnumber_t agno = cur->bc_private.a.agno;
union xfs_btree_rec *rec;
int error;
@@ -210,7 +213,43 @@ xfs_rmap_get_rec(
if (error || !*stat)
return error;
- return xfs_rmap_btrec_to_irec(rec, irec);
+ if (xfs_rmap_btrec_to_irec(rec, irec))
+ goto out_bad_rec;
+
+ if (irec->rm_blockcount == 0)
+ goto out_bad_rec;
+ if (irec->rm_startblock <= XFS_AGFL_BLOCK(mp)) {
+ if (irec->rm_owner != XFS_RMAP_OWN_FS)
+ goto out_bad_rec;
+ if (irec->rm_blockcount != XFS_AGFL_BLOCK(mp) + 1)
+ goto out_bad_rec;
+ } else {
+ /* check for valid extent range, including overflow */
+ if (!xfs_verify_agbno(mp, agno, irec->rm_startblock))
+ goto out_bad_rec;
+ if (irec->rm_startblock >
+ irec->rm_startblock + irec->rm_blockcount)
+ goto out_bad_rec;
+ if (!xfs_verify_agbno(mp, agno,
+ irec->rm_startblock + irec->rm_blockcount - 1))
+ goto out_bad_rec;
+ }
+
+ if (!(xfs_verify_ino(mp, irec->rm_owner) ||
+ (irec->rm_owner <= XFS_RMAP_OWN_FS &&
+ irec->rm_owner >= XFS_RMAP_OWN_MIN)))
+ goto out_bad_rec;
+
+ return 0;
+out_bad_rec:
+ xfs_warn(mp,
+ "Reverse Mapping BTree record corruption in AG %d detected!",
+ agno);
+ xfs_warn(mp,
+ "Owner 0x%llx, flags 0x%x, start block 0x%x block count 0x%x",
+ irec->rm_owner, irec->rm_flags, irec->rm_startblock,
+ irec->rm_blockcount);
+ return -EFSCORRUPTED;
}
struct xfs_find_left_neighbor_info {