| Message ID | 20240617194947.1928008-1-alexthreed@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fs: btrfs: fix out of bounds write | expand |
在 2024/6/18 05:19, Alex Shumsky 写道: > Fix btrfs_read/read_and_truncate_page write out of bounds of destination > buffer. Old behavior break bootstd malloc'd buffers of exact file size. > Previously this OOB write have not been noticed because distroboot usually > read files into huge static memory areas. > > Signed-off-by: Alex Shumsky <alexthreed@gmail.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Thanks, Qu > --- > > fs/btrfs/inode.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index 4691612eda..b51f578b49 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -640,7 +640,7 @@ static int read_and_truncate_page(struct btrfs_path *path, > extent_type = btrfs_file_extent_type(leaf, fi); > if (extent_type == BTRFS_FILE_EXTENT_INLINE) { > ret = btrfs_read_extent_inline(path, fi, buf); > - memcpy(dest, buf + page_off, min(page_len, ret)); > + memcpy(dest, buf + page_off, min(min(page_len, ret), len)); > free(buf); > return len; > } > @@ -652,7 +652,7 @@ static int read_and_truncate_page(struct btrfs_path *path, > free(buf); > return ret; > } > - memcpy(dest, buf + page_off, page_len); > + memcpy(dest, buf + page_off, min(page_len, len)); > free(buf); > return len; > }
On Mon, 17 Jun 2024 22:49:47 +0300, Alex Shumsky wrote: > Fix btrfs_read/read_and_truncate_page write out of bounds of destination > buffer. Old behavior break bootstd malloc'd buffers of exact file size. > Previously this OOB write have not been noticed because distroboot usually > read files into huge static memory areas. > > Signed-off-by: Alex Shumsky <alexthreed@gmail.com> > --- > > fs/btrfs/inode.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index 4691612eda..b51f578b49 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -640,7 +640,7 @@ static int read_and_truncate_page(struct btrfs_path *path, > extent_type = btrfs_file_extent_type(leaf, fi); > if (extent_type == BTRFS_FILE_EXTENT_INLINE) { > ret = btrfs_read_extent_inline(path, fi, buf); > - memcpy(dest, buf + page_off, min(page_len, ret)); > + memcpy(dest, buf + page_off, min(min(page_len, ret), len)); This looks (still) broken for the compressed inline extent error paths, where ret=-errno . nit: please prefix your patch subject with "uboot" so that casual linux-btrfs readers like me don't get confused by matching kernel file paths.
On Mon, Jun 17, 2024 at 10:49:47PM +0300, Alex Shumsky wrote: > Fix btrfs_read/read_and_truncate_page write out of bounds of destination > buffer. Old behavior break bootstd malloc'd buffers of exact file size. > Previously this OOB write have not been noticed because distroboot usually > read files into huge static memory areas. > > Signed-off-by: Alex Shumsky <alexthreed@gmail.com> Could you add a Fixes tag? regards, dan carpenter
On Mon, 17 Jun 2024 22:49:47 +0300 Alex Shumsky <alexthreed@gmail.com> wrote: > Fix btrfs_read/read_and_truncate_page write out of bounds of destination > buffer. Old behavior break bootstd malloc'd buffers of exact file size. > Previously this OOB write have not been noticed because distroboot usually > read files into huge static memory areas. > > Signed-off-by: Alex Shumsky <alexthreed@gmail.com> > --- > > fs/btrfs/inode.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index 4691612eda..b51f578b49 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -640,7 +640,7 @@ static int read_and_truncate_page(struct btrfs_path *path, > extent_type = btrfs_file_extent_type(leaf, fi); > if (extent_type == BTRFS_FILE_EXTENT_INLINE) { > ret = btrfs_read_extent_inline(path, fi, buf); > - memcpy(dest, buf + page_off, min(page_len, ret)); > + memcpy(dest, buf + page_off, min(min(page_len, ret), len)); Use min3() instead of min(min())
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 4691612eda..b51f578b49 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -640,7 +640,7 @@ static int read_and_truncate_page(struct btrfs_path *path, extent_type = btrfs_file_extent_type(leaf, fi); if (extent_type == BTRFS_FILE_EXTENT_INLINE) { ret = btrfs_read_extent_inline(path, fi, buf); - memcpy(dest, buf + page_off, min(page_len, ret)); + memcpy(dest, buf + page_off, min(min(page_len, ret), len)); free(buf); return len; } @@ -652,7 +652,7 @@ static int read_and_truncate_page(struct btrfs_path *path, free(buf); return ret; } - memcpy(dest, buf + page_off, page_len); + memcpy(dest, buf + page_off, min(page_len, len)); free(buf); return len; }
Fix btrfs_read/read_and_truncate_page write out of bounds of destination buffer. Old behavior break bootstd malloc'd buffers of exact file size. Previously this OOB write have not been noticed because distroboot usually read files into huge static memory areas. Signed-off-by: Alex Shumsky <alexthreed@gmail.com> --- fs/btrfs/inode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)