From: Bryam Vargas <hexlabsecurity@proton.me> stable inclusion from stable-v5.10.261 commit eeb0f3e193f8e523d03e4c9e084f6b4875f50e8e category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16618 CVE: CVE-2026-64322 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 3ec997bd5508e9b25210b5bbec89031629cdb093 upstream. udf_load_sparable_map() accepts a sparing table when sizeof(*st) + le16_to_cpu(st->reallocationTableLen) > sb->s_blocksize is false, i.e. it treats reallocationTableLen as a number of BYTES that must fit in the block. But the table is walked as an array of 8-byte sparingEntry elements: for (i = 0; i < le16_to_cpu(st->reallocationTableLen); i++) { struct sparingEntry *entry = &st->mapEntry[i]; ... entry->origLocation ... } in udf_get_pblock_spar15() and udf_relocate_blocks(). A reallocationTableLen of N therefore passes the check whenever sizeof(*st) + N <= blocksize, yet the consumers index sizeof(*st) + N * sizeof(struct sparingEntry) bytes -- up to ~8x the block. On a crafted UDF image this is an out-of-bounds read in udf_get_pblock_spar15(); udf_relocate_blocks() additionally feeds the same length to udf_update_tag(), whose crc_itu_t() reads far past the block, and its memmove() through st->mapEntry[] is an out-of-bounds write. Validate reallocationTableLen as the entry count it is, with struct_size(). Fixes: 1df2ae31c724 ("udf: Fortify loading of sparing table") Cc: stable@vger.kernel.org Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me> Link: https://patch.msgid.link/20260612-b4-disp-91780c4e-v1-1-f15112ff6882@proton.... Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Lu Chentao <luchentao1@huawei.com> --- fs/udf/super.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/udf/super.c b/fs/udf/super.c index aa50c6d0e1df..f14fe6cac643 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -1387,11 +1387,12 @@ static int udf_load_sparable_map(struct super_block *sb, st = (struct sparingTable *)bh->b_data; if (ident != 0 || strncmp(st->sparingIdent.ident, UDF_ID_SPARING, strlen(UDF_ID_SPARING)) || - sizeof(*st) + le16_to_cpu(st->reallocationTableLen) > + struct_size(st, mapEntry, + le16_to_cpu(st->reallocationTableLen)) > sb->s_blocksize) { brelse(bh); continue; } -- 2.52.0