Date: Tue, 09 Apr 2024 21:51:53 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 278281] /usr/sbin/fstyp potential read through wild pointer Message-ID: <bug-278281-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D278281 Bug ID: 278281 Summary: /usr/sbin/fstyp potential read through wild pointer Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Severity: Affects Some People Priority: --- Component: bin Assignee: bugs@FreeBSD.org Reporter: rtm@lcs.mit.edu Created attachment 249865 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=3D249865&action= =3Dedit file system image that causes fstyp's fstyp_ntfs() to crash This code in fstyp's ntfs.c fstyp_ntfs(): filerecp =3D read_buf(fp, voloff, recsize); ...; for (ap =3D filerecp + fr->fr_attroff; atr =3D (struct ntfs_attr *)ap, (int)atr->a_type !=3D -1; ap +=3D atr->reclen) { can cause ap and atr to have crazy values if the filesystem being inspected provides something bad for atr->reclen. If atr->reclen =3D=3D 0, it's an infinite loop. Separately, in hammer2.c read_label(), "vols[i] =3D read_buf(...)" can be NULL, but the next line dereferences vols[i] without checking. I've attached a demo for the first bug: # uname -a FreeBSD stock14 15.0-CURRENT FreeBSD 15.0-CURRENT #21 main-n269145-3e1c8a35f741-dirty: Sat Apr 6 15:52:00 AST 2024=20=20=20=20 root@stock14:/usr/obj/usr/src/amd64.amd64/sys/GENERIC amd64 # gunzip fstyp6b.img.gz=20 # fstyp -u -l fstyp6b.img=20 Segmentation fault Program received signal SIGSEGV, Segmentation fault. Address not mapped to object. fstyp_ntfs (fp=3D0x80131f330, label=3D0x7fffffffe7f0 "", size=3D257) at /usr/src/usr.sbin/fstyp/ntfs.c:169 169 atr =3D (struct ntfs_attr *)ap, (int)atr->a_type !=3D -= 1; (gdb) where #0 fstyp_ntfs (fp=3D0x80131f330, label=3D0x7fffffffe7f0 "", size=3D257) at /usr/src/usr.sbin/fstyp/ntfs.c:169 #1 0x0000000001024a6c in main (argc=3D<optimized out>, argv=3D<optimized o= ut>) at /usr/src/usr.sbin/fstyp/fstyp.c:240 --=20 You are receiving this mail because: You are the assignee for the bug.=
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