Commit 71dac248 authored May 06, 2024 by Kent Overstreet

bcachefs: BCH_SB_LAYOUT_SIZE_BITS_MAX



Define a constant for the max superblock size, to avoid a too-large
shift.

Reported-by:  <syzbot+a8b0fb419355c91dda7f@syzkaller.appspotmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

parent 88ab1018

fs/bcachefs/bcachefs_format.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -903,6 +903,8 @@ unsigned bcachefs_metadata_required_upgrade_below = bcachefs_metadata_version_re
		#define BCH_SB_SECTOR 8
		#define BCH_SB_MEMBERS_MAX 64 /* XXX kill */

		#define BCH_SB_LAYOUT_SIZE_BITS_MAX 16 /* 32 MB */

		struct bch_sb_layout {
		__uuid_t magic; /* bcachefs superblock UUID */
		__u8 layout_type;

fs/bcachefs/super-io.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -649,7 +649,7 @@ static int read_one_super(struct bch_sb_handle *sb, u64 offset, struct printbuf

		bytes = vstruct_bytes(sb->sb);

		if (bytes > 512 << sb->sb->layout.sb_max_size_bits) {
		if (bytes > 512ULL << min(BCH_SB_LAYOUT_SIZE_BITS_MAX, sb->sb->layout.sb_max_size_bits)) {
		prt_printf(err, "Invalid superblock: too big (got %zu bytes, layout max %lu)",
		bytes, 512UL << sb->sb->layout.sb_max_size_bits);
		return -BCH_ERR_invalid_sb_too_big;