fs/ntfs3: Fix warning in ni_fiemap

Use local runs_tree instead of cached. This way excludes rw_semaphore lock.

Reported-by: syzbot+1c25748a40fe79b8a119@syzkaller.appspotmail.com
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

diff --git a/fs/ntfs3/attrib.c b/fs/ntfs3/attrib.c
index 0763202..8d789b0 100644 (file)
--- a/fs/ntfs3/attrib.c
+++ b/fs/ntfs3/attrib.c
@@ -977,7 +977,7 @@ int attr_data_get_block(struct ntfs_inode *ni, CLST vcn, CLST clen, CLST *lcn,
 
        /* Check for compressed frame. */
        err = attr_is_frame_compressed(ni, attr_b, vcn >> NTFS_LZNT_CUNIT,
-                                      &hint);
+                                      &hint, run);
        if (err)
                goto out;
 
@@ -1521,16 +1521,16 @@ out:
  * attr_is_frame_compressed - Used to detect compressed frame.
  *
  * attr - base (primary) attribute segment.
+ * run  - run to use, usually == &ni->file.run.
  * Only base segments contains valid 'attr->nres.c_unit'
  */
 int attr_is_frame_compressed(struct ntfs_inode *ni, struct ATTRIB *attr,
-                            CLST frame, CLST *clst_data)
+                            CLST frame, CLST *clst_data, struct runs_tree *run)
 {
        int err;
        u32 clst_frame;
        CLST clen, lcn, vcn, alen, slen, vcn_next;
        size_t idx;
-       struct runs_tree *run;
 
        *clst_data = 0;
 
@@ -1542,7 +1542,6 @@ int attr_is_frame_compressed(struct ntfs_inode *ni, struct ATTRIB *attr,
 
        clst_frame = 1u << attr->nres.c_unit;
        vcn = frame * clst_frame;
-       run = &ni->file.run;
 
        if (!run_lookup_entry(run, vcn, &lcn, &clen, &idx)) {
                err = attr_load_runs_vcn(ni, attr->type, attr_name(attr),
@@ -1678,7 +1677,7 @@ int attr_allocate_frame(struct ntfs_inode *ni, CLST frame, size_t compr_size,
        if (err)
                goto out;
 
-       err = attr_is_frame_compressed(ni, attr_b, frame, &clst_data);
+       err = attr_is_frame_compressed(ni, attr_b, frame, &clst_data, run);
        if (err)
                goto out;
 

diff --git a/fs/ntfs3/frecord.c b/fs/ntfs3/frecord.c
index 41c7ffa..c33e818 100644 (file)
--- a/fs/ntfs3/frecord.c
+++ b/fs/ntfs3/frecord.c
@@ -1900,46 +1900,6 @@ enum REPARSE_SIGN ni_parse_reparse(struct ntfs_inode *ni, struct ATTRIB *attr,
        return REPARSE_LINK;
 }
 
-/*
- * fiemap_fill_next_extent_k - a copy of fiemap_fill_next_extent
- * but it uses 'fe_k' instead of fieinfo->fi_extents_start
- */
-static int fiemap_fill_next_extent_k(struct fiemap_extent_info *fieinfo,
-                                    struct fiemap_extent *fe_k, u64 logical,
-                                    u64 phys, u64 len, u32 flags)
-{
-       struct fiemap_extent extent;
-
-       /* only count the extents */
-       if (fieinfo->fi_extents_max == 0) {
-               fieinfo->fi_extents_mapped++;
-               return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
-       }
-
-       if (fieinfo->fi_extents_mapped >= fieinfo->fi_extents_max)
-               return 1;
-
-       if (flags & FIEMAP_EXTENT_DELALLOC)
-               flags |= FIEMAP_EXTENT_UNKNOWN;
-       if (flags & FIEMAP_EXTENT_DATA_ENCRYPTED)
-               flags |= FIEMAP_EXTENT_ENCODED;
-       if (flags & (FIEMAP_EXTENT_DATA_TAIL | FIEMAP_EXTENT_DATA_INLINE))
-               flags |= FIEMAP_EXTENT_NOT_ALIGNED;
-
-       memset(&extent, 0, sizeof(extent));
-       extent.fe_logical = logical;
-       extent.fe_physical = phys;
-       extent.fe_length = len;
-       extent.fe_flags = flags;
-
-       memcpy(fe_k + fieinfo->fi_extents_mapped, &extent, sizeof(extent));
-
-       fieinfo->fi_extents_mapped++;
-       if (fieinfo->fi_extents_mapped == fieinfo->fi_extents_max)
-               return 1;
-       return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
-}
-
 /*
  * ni_fiemap - Helper for file_fiemap().
  *
@@ -1950,11 +1910,9 @@ int ni_fiemap(struct ntfs_inode *ni, struct fiemap_extent_info *fieinfo,
              __u64 vbo, __u64 len)
 {
        int err = 0;
-       struct fiemap_extent *fe_k = NULL;
        struct ntfs_sb_info *sbi = ni->mi.sbi;
        u8 cluster_bits = sbi->cluster_bits;
-       struct runs_tree *run;
-       struct rw_semaphore *run_lock;
+       struct runs_tree run;
        struct ATTRIB *attr;
        CLST vcn = vbo >> cluster_bits;
        CLST lcn, clen;
@@ -1965,13 +1923,11 @@ int ni_fiemap(struct ntfs_inode *ni, struct fiemap_extent_info *fieinfo,
        u32 flags;
        bool ok;
 
+       run_init(&run);
        if (S_ISDIR(ni->vfs_inode.i_mode)) {
-               run = &ni->dir.alloc_run;
                attr = ni_find_attr(ni, NULL, NULL, ATTR_ALLOC, I30_NAME,
                                    ARRAY_SIZE(I30_NAME), NULL, NULL);
-               run_lock = &ni->dir.run_lock;
        } else {
-               run = &ni->file.run;
                attr = ni_find_attr(ni, NULL, NULL, ATTR_DATA, NULL, 0, NULL,
                                    NULL);
                if (!attr) {
@@ -1986,7 +1942,6 @@ int ni_fiemap(struct ntfs_inode *ni, struct fiemap_extent_info *fieinfo,
                                "fiemap is not supported for compressed file (cp -r)");
                        goto out;
                }
-               run_lock = &ni->file.run_lock;
        }
 
        if (!attr || !attr->non_res) {
@@ -1998,51 +1953,33 @@ int ni_fiemap(struct ntfs_inode *ni, struct fiemap_extent_info *fieinfo,
                goto out;
        }
 
-       /*
-        * To avoid lock problems replace pointer to user memory by pointer to kernel memory.
-        */
-       fe_k = kmalloc_array(fieinfo->fi_extents_max,
-                            sizeof(struct fiemap_extent),
-                            GFP_NOFS | __GFP_ZERO);
-       if (!fe_k) {
-               err = -ENOMEM;
-               goto out;
-       }
-
        end = vbo + len;
        alloc_size = le64_to_cpu(attr->nres.alloc_size);
        if (end > alloc_size)
                end = alloc_size;
 
-       down_read(run_lock);
 
        while (vbo < end) {
                if (idx == -1) {
-                       ok = run_lookup_entry(run, vcn, &lcn, &clen, &idx);
+                       ok = run_lookup_entry(&run, vcn, &lcn, &clen, &idx);
                } else {
                        CLST vcn_next = vcn;
 
-                       ok = run_get_entry(run, ++idx, &vcn, &lcn, &clen) &&
+                       ok = run_get_entry(&run, ++idx, &vcn, &lcn, &clen) &&
                             vcn == vcn_next;
                        if (!ok)
                                vcn = vcn_next;
                }
 
                if (!ok) {
-                       up_read(run_lock);
-                       down_write(run_lock);
-
                        err = attr_load_runs_vcn(ni, attr->type,
                                                 attr_name(attr),
-                                                attr->name_len, run, vcn);
-
-                       up_write(run_lock);
-                       down_read(run_lock);
+                                                attr->name_len, &run, vcn);
 
                        if (err)
                                break;
 
-                       ok = run_lookup_entry(run, vcn, &lcn, &clen, &idx);
+                       ok = run_lookup_entry(&run, vcn, &lcn, &clen, &idx);
 
                        if (!ok) {
                                err = -EINVAL;
@@ -2067,8 +2004,9 @@ int ni_fiemap(struct ntfs_inode *ni, struct fiemap_extent_info *fieinfo,
                } else if (is_attr_compressed(attr)) {
                        CLST clst_data;
 
-                       err = attr_is_frame_compressed(
-                               ni, attr, vcn >> attr->nres.c_unit, &clst_data);
+                       err = attr_is_frame_compressed(ni, attr,
+                                                      vcn >> attr->nres.c_unit,
+                                                      &clst_data, &run);
                        if (err)
                                break;
                        if (clst_data < NTFS_LZNT_CLUSTERS)
@@ -2097,8 +2035,8 @@ int ni_fiemap(struct ntfs_inode *ni, struct fiemap_extent_info *fieinfo,
                        if (vbo + dlen >= end)
                                flags |= FIEMAP_EXTENT_LAST;
 
-                       err = fiemap_fill_next_extent_k(fieinfo, fe_k, vbo, lbo,
-                                                       dlen, flags);
+                       err = fiemap_fill_next_extent(fieinfo, vbo, lbo, dlen,
+                                                     flags);
 
                        if (err < 0)
                                break;
@@ -2119,8 +2057,7 @@ int ni_fiemap(struct ntfs_inode *ni, struct fiemap_extent_info *fieinfo,
                if (vbo + bytes >= end)
                        flags |= FIEMAP_EXTENT_LAST;
 
-               err = fiemap_fill_next_extent_k(fieinfo, fe_k, vbo, lbo, bytes,
-                                               flags);
+               err = fiemap_fill_next_extent(fieinfo, vbo, lbo, bytes, flags);
                if (err < 0)
                        break;
                if (err == 1) {
@@ -2131,19 +2068,8 @@ int ni_fiemap(struct ntfs_inode *ni, struct fiemap_extent_info *fieinfo,
                vbo += bytes;
        }
 
-       up_read(run_lock);
-
-       /*
-        * Copy to user memory out of lock
-        */
-       if (copy_to_user(fieinfo->fi_extents_start, fe_k,
-                        fieinfo->fi_extents_max *
-                                sizeof(struct fiemap_extent))) {
-               err = -EFAULT;
-       }
-
 out:
-       kfree(fe_k);
+       run_close(&run);
        return err;
 }
 
@@ -2672,7 +2598,8 @@ int ni_read_frame(struct ntfs_inode *ni, u64 frame_vbo, struct page **pages,
                down_write(&ni->file.run_lock);
                run_truncate_around(run, le64_to_cpu(attr->nres.svcn));
                frame = frame_vbo >> (cluster_bits + NTFS_LZNT_CUNIT);
-               err = attr_is_frame_compressed(ni, attr, frame, &clst_data);
+               err = attr_is_frame_compressed(ni, attr, frame, &clst_data,
+                                              run);
                up_write(&ni->file.run_lock);
                if (err)
                        goto out1;

diff --git a/fs/ntfs3/ntfs_fs.h b/fs/ntfs3/ntfs_fs.h
index 26e1e13..cd8e837 100644 (file)
--- a/fs/ntfs3/ntfs_fs.h
+++ b/fs/ntfs3/ntfs_fs.h
@@ -446,7 +446,8 @@ int attr_wof_frame_info(struct ntfs_inode *ni, struct ATTRIB *attr,
                        struct runs_tree *run, u64 frame, u64 frames,
                        u8 frame_bits, u32 *ondisk_size, u64 *vbo_data);
 int attr_is_frame_compressed(struct ntfs_inode *ni, struct ATTRIB *attr,
-                            CLST frame, CLST *clst_data);
+                            CLST frame, CLST *clst_data,
+                            struct runs_tree *run);
 int attr_allocate_frame(struct ntfs_inode *ni, CLST frame, size_t compr_size,
                        u64 new_valid);
 int attr_collapse_range(struct ntfs_inode *ni, u64 vbo, u64 bytes);