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| author | Thorsten Blum <thorsten.blum@toblux.com> | 2024-07-31 01:02:02 +0300 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2024-08-27 06:40:06 +0300 |
| commit | 01cdf03b1378f2d860d4eb5951895a92002226a3 (patch) | |
| tree | a06dbfc1bc770339720d990c54ef410eb3e66be9 | |
| parent | 736c24e62e7e1f5d00fb5b750bb7c13c56410d07 (diff) | |
| download | linux-01cdf03b1378f2d860d4eb5951895a92002226a3.tar.xz | |
ext4: annotate struct ext4_xattr_inode_array with __counted_by()
Add the __counted_by compiler attribute to the flexible array member
inodes to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
CONFIG_FORTIFY_SOURCE.
Remove the now obsolete comment on the count field.
In ext4_expand_inode_array(), use struct_size() instead of offsetof()
and remove the local variable count. Increment the count field before
adding a new inode to the inodes array.
Compile-tested only.
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Link: https://patch.msgid.link/20240730220200.410939-3-thorsten.blum@toblux.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| -rw-r--r-- | fs/ext4/xattr.c | 22 | ||||
| -rw-r--r-- | fs/ext4/xattr.h | 4 |
2 files changed, 12 insertions, 14 deletions
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 31c5189e131f..c14a674c3e3d 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -2879,33 +2879,31 @@ ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array, if (*ea_inode_array == NULL) { /* * Start with 15 inodes, so it fits into a power-of-two size. - * If *ea_inode_array is NULL, this is essentially offsetof() */ - (*ea_inode_array) = - kmalloc(offsetof(struct ext4_xattr_inode_array, - inodes[EIA_MASK]), - GFP_NOFS); + (*ea_inode_array) = kmalloc( + struct_size(*ea_inode_array, inodes, EIA_MASK), + GFP_NOFS); if (*ea_inode_array == NULL) return -ENOMEM; (*ea_inode_array)->count = 0; } else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) { /* expand the array once all 15 + n * 16 slots are full */ struct ext4_xattr_inode_array *new_array = NULL; - int count = (*ea_inode_array)->count; - /* if new_array is NULL, this is essentially offsetof() */ new_array = kmalloc( - offsetof(struct ext4_xattr_inode_array, - inodes[count + EIA_INCR]), - GFP_NOFS); + struct_size(*ea_inode_array, inodes, + (*ea_inode_array)->count + EIA_INCR), + GFP_NOFS); if (new_array == NULL) return -ENOMEM; memcpy(new_array, *ea_inode_array, - offsetof(struct ext4_xattr_inode_array, inodes[count])); + struct_size(*ea_inode_array, inodes, + (*ea_inode_array)->count)); kfree(*ea_inode_array); *ea_inode_array = new_array; } - (*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode; + (*ea_inode_array)->count++; + (*ea_inode_array)->inodes[(*ea_inode_array)->count - 1] = inode; return 0; } diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h index 7df0d77643c7..b25c2d7b5f99 100644 --- a/fs/ext4/xattr.h +++ b/fs/ext4/xattr.h @@ -129,8 +129,8 @@ struct ext4_xattr_ibody_find { }; struct ext4_xattr_inode_array { - unsigned int count; /* # of used items in the array */ - struct inode *inodes[]; + unsigned int count; + struct inode *inodes[] __counted_by(count); }; extern const struct xattr_handler ext4_xattr_user_handler; |