bcachefs: Remove incorrect __counted_by annotation

commit 6846100b00d97d3d6f05766ae86a0d821d849e78 upstream.

This actually reverts 86e92eeeb2 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alan Huang 2025-05-02 04:01:31 +08:00 committed by Greg Kroah-Hartman
parent dab2a13059
commit 6b6cd38910

View File

@ -13,7 +13,13 @@ struct bch_xattr {
__u8 x_type; __u8 x_type;
__u8 x_name_len; __u8 x_name_len;
__le16 x_val_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); } __packed __aligned(8);
#endif /* _BCACHEFS_XATTR_FORMAT_H */ #endif /* _BCACHEFS_XATTR_FORMAT_H */