system/freebsd-src
system/freebsd-src
1
0
Fork 0
mirror of https://github.com/freebsd/freebsd-src synced 2024-07-22 10:48:02 +00:00
Code Issues Actions 2 Packages Projects Releases Wiki Activity

Updates to UFS/FFS superblock integrity checks when reading a superblock.

Browse source 
Have to add a check that the computed cylinder group size does not
exceed the block size of the filesystem.

It is also necessary to validate additional parameters when a
superblock is going to be used in read-only mode if its supplementary
information is going to be read in to ensure that the size and
location of the supplementary information is valid. Also when a
warning is raised let it be accepted, but bound the flagged field
to the value checked by the warning.

No legitimate superblocks should fail as a result of these changes.

Reported by:  Bob Prohaska, John-Mark Gurney, and Mark Millard
Tested by:    Peter Holm
Reviewed by:  Peter Holm
MFC after:    2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D38668
This commit is contained in:
Kirk McKusick 2023-03-07 14:59:56 -08:00
parent 1a718f7a3b
commit 0eabe33087
1 changed files with 28 additions and 10 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

38
sys/ufs/ffs/ffs_subr.c
View file

@ -347,6 +347,8 @@ readsuper(void *devfd, struct fs **fsp, off_t sblockloc, int flags,
#lhs, (intmax_t)lhs, #op, #rhs, (intmax_t)rhs, wmsg);\
if (error == 0) \
error = warnerr; \
if (warnerr == 0) \
lhs = rhs; \
}
#define FCHK2(lhs1, op1, rhs1, lhs2, op2, rhs2, fmt) \
if (lhs1 op1 rhs1 && lhs2 op2 rhs2) { \
@ -360,16 +362,6 @@ readsuper(void *devfd, struct fs **fsp, off_t sblockloc, int flags,
if (error == 0) \
error = ENOENT; \
}
#define WCHK2(lhs1, op1, rhs1, lhs2, op2, rhs2, fmt) \
if (lhs1 op1 rhs1 && lhs2 op2 rhs2) { \
MPRINT("UFS%d superblock failed: %s (" #fmt ") %s %s (" \
#fmt ") && %s (" #fmt ") %s %s (" #fmt ")%s\n", \
fs->fs_magic == FS_UFS1_MAGIC ? 1 : 2, #lhs1, \
(intmax_t)lhs1, #op1, #rhs1, (intmax_t)rhs1, #lhs2, \
(intmax_t)lhs2, #op2, #rhs2, (intmax_t)rhs2, wmsg); \
if (error == 0) \
error = warnerr; \
}
static int
validate_sblock(struct fs *fs, int flags)
@ -408,6 +400,7 @@ validate_sblock(struct fs *fs, int flags)
} else if (fs->fs_magic == FS_UFS1_MAGIC) {
FCHK(fs->fs_sblockloc, <, 0, %jd);
FCHK(fs->fs_sblockloc, >, SBLOCK_UFS1, %jd);
FCHK(fs->fs_old_ncyl, !=, fs->fs_ncg, %jd);
}
FCHK(fs->fs_frag, <, 1, %jd);
FCHK(fs->fs_frag, >, MAXFRAG, %jd);
@ -431,6 +424,30 @@ validate_sblock(struct fs *fs, int flags)
FCHK(fs->fs_sblkno, !=, roundup(
howmany(fs->fs_sblockloc + SBLOCKSIZE, fs->fs_fsize),
fs->fs_frag), %jd);
FCHK(CGSIZE(fs), >, fs->fs_bsize, %jd);
/* Only need to validate these if reading in csum data */
if ((flags & UFS_NOCSUM) != 0)
return (error);
FCHK((u_int64_t)fs->fs_ipg * fs->fs_ncg, >,
(((int64_t)(1)) << 32) - INOPB(fs), %jd);
FCHK(fs->fs_cstotal.cs_nifree, <, 0, %jd);
FCHK(fs->fs_cstotal.cs_nifree, >,
(u_int64_t)fs->fs_ipg * fs->fs_ncg, %jd);
FCHK(fs->fs_cstotal.cs_ndir, >,
((u_int64_t)fs->fs_ipg * fs->fs_ncg) -
fs->fs_cstotal.cs_nifree, %jd);
FCHK(fs->fs_size, <, 8 * fs->fs_frag, %jd);
FCHK(fs->fs_size, <=, ((int64_t)fs->fs_ncg - 1) * fs->fs_fpg,
%jd);
FCHK(fs->fs_size, >, (int64_t)fs->fs_ncg * fs->fs_fpg, %jd);
FCHK(fs->fs_csaddr, <, 0, %jd);
FCHK(fs->fs_cssize, !=,
fragroundup(fs, fs->fs_ncg * sizeof(struct csum)), %jd);
FCHK(dtog(fs, fs->fs_csaddr), >, fs->fs_ncg, %jd);
FCHK(fs->fs_csaddr, <, cgdmin(fs, dtog(fs, fs->fs_csaddr)),
%jd);
FCHK(dtog(fs, fs->fs_csaddr + howmany(fs->fs_cssize,
fs->fs_fsize)), >, dtog(fs, fs->fs_csaddr), %jd);
return (error);
}
if (fs->fs_magic == FS_UFS2_MAGIC) {
@ -511,6 +528,7 @@ validate_sblock(struct fs *fs, int flags)
FCHK(fs->fs_old_cgoffset, <, 0, %jd);
FCHK2(fs->fs_old_cgoffset, >, 0, ~fs->fs_old_cgmask, <, 0, %jd);
FCHK(fs->fs_old_cgoffset * (~fs->fs_old_cgmask), >, fs->fs_fpg, %jd);
FCHK(CGSIZE(fs), >, fs->fs_bsize, %jd);
/*
* If anything has failed up to this point, it is usafe to proceed
* as checks below may divide by zero or make other fatal calculations.