diff options
| author | Alan Huang <mmpgouride@gmail.com> | 2025-05-02 04:01:31 +0800 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2025-05-01 16:38:58 -0400 |
| commit | 6846100b00d97d3d6f05766ae86a0d821d849e78 (patch) | |
| tree | afa76c12f415721ac1ba9d9562f48c7c1df8de20 /fs | |
| parent | 28580052e634fe8fa327e6f25c35590374be754b (diff) | |
bcachefs: Remove incorrect __counted_by annotation
This actually reverts 86e92eeeb237 ("bcachefs: Annotate struct bch_xattr
with __counted_by()").
After the x_name, there is a value. According to the disscussion[1],
__counted_by assumes that the flexible array member contains exactly
the amount of elements that are specified. Now there are users came across
a false positive detection of an out of bounds write caused by
the __counted_by here[2], so revert that.
[1] https://lore.kernel.org/lkml/Zv8VDKWN1GzLRT-_@archlinux/T/#m0ce9541c5070146320efd4f928cc1ff8de69e9b2
[2] https://privatebin.net/?a0d4e97d590d71e1#9bLmp2Kb5NU6X6cZEucchDcu88HzUQwHUah8okKPReEt
Signed-off-by: Alan Huang <mmpgouride@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/bcachefs/xattr_format.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/fs/bcachefs/xattr_format.h b/fs/bcachefs/xattr_format.h index c7916011ef34..67426e33d04e 100644 --- a/fs/bcachefs/xattr_format.h +++ b/fs/bcachefs/xattr_format.h @@ -13,7 +13,13 @@ struct bch_xattr { __u8 x_type; __u8 x_name_len; __le16 x_val_len; - __u8 x_name[] __counted_by(x_name_len); + /* + * x_name contains the name and value counted by + * x_name_len + x_val_len. The introduction of + * __counted_by(x_name_len) caused a false positive + * detection of an out of bounds write. + */ + __u8 x_name[]; } __packed __aligned(8); #endif /* _BCACHEFS_XATTR_FORMAT_H */ |