git: 0db7f4b419db - stable/12 - udf: Reject read requests with an invalid length

The branch stable/12 has been updated by jhb:

URL: https://cgit.FreeBSD.org/src/commit/?id=0db7f4b419dbaa2c23a737393d35564cd0b2f35a

commit 0db7f4b419dbaa2c23a737393d35564cd0b2f35a
Author:     John Baldwin <jhb@FreeBSD.org>
AuthorDate: 2023-08-04 23:40:19 +0000
Commit:     John Baldwin <jhb@FreeBSD.org>
CommitDate: 2023-09-06 20:02:33 +0000

    udf: Reject read requests with an invalid length
    
    - If the size is negative or if rounding it up to a multiple of
      the block size overflows, fail the read request with ERANGE.
    
    - While here, add a sanity check that the ICB length for the root
      directory is at least as long as a minimum-sized file entry.
    
    PR:             257768
    Reported by:    Robert Morris <rtm@lcs.mit.edu>
    MFC after:      1 week
    Sponsored by:   FreeBSD Foundation
    Differential Revision:  https://reviews.freebsd.org/D41220
    
    (cherry picked from commit c70e615051b00671d54651d99af5cdec4b091d92)
---
 sys/fs/udf/udf.h        | 4 +++-
 sys/fs/udf/udf_vfsops.c | 5 +++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/sys/fs/udf/udf.h b/sys/fs/udf/udf.h
index 33bf4539c41b..507c75692433 100644
--- a/sys/fs/udf/udf.h
+++ b/sys/fs/udf/udf.h
@@ -97,8 +97,10 @@ struct ifid {
 MALLOC_DECLARE(M_UDFFENTRY);
 
 static __inline int
-udf_readdevblks(struct udf_mnt *udfmp, int sector, int size, struct buf **bp)
+udf_readdevblks(struct udf_mnt *udfmp, daddr_t sector, int size, struct buf **bp)
 {
+	if (size < 0 || size + udfmp->bmask < size)
+		return (ERANGE);
 	return (RDSECTOR(udfmp->im_devvp, sector,
 			 (size + udfmp->bmask) & ~udfmp->bmask, bp));
 }
diff --git a/sys/fs/udf/udf_vfsops.c b/sys/fs/udf/udf_vfsops.c
index af249e91ed9d..0e450da83808 100644
--- a/sys/fs/udf/udf_vfsops.c
+++ b/sys/fs/udf/udf_vfsops.c
@@ -478,6 +478,11 @@ udf_mountfs(struct vnode *devvp, struct mount *mp)
 	 */
 	sector = le32toh(udfmp->root_icb.loc.lb_num) + udfmp->part_start;
 	size = le32toh(udfmp->root_icb.len);
+	if (size < UDF_FENTRY_SIZE) {
+		printf("Invalid root directory file entry length %u\n",
+		    size);
+		goto bail;
+	}
 	if ((error = udf_readdevblks(udfmp, sector, size, &bp)) != 0) {
 		printf("Cannot read sector %d\n", sector);
 		goto bail;