git: 0eabe33087d8 - main - Updates to UFS/FFS superblock integrity checks when reading a superblock.
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Date: Tue, 07 Mar 2023 23:02:40 UTC
The branch main has been updated by mckusick: URL: https://cgit.FreeBSD.org/src/commit/?id=0eabe33087d8cb69ae800daae322f12a8f16bd10 commit 0eabe33087d8cb69ae800daae322f12a8f16bd10 Author: Kirk McKusick <mckusick@FreeBSD.org> AuthorDate: 2023-03-07 22:59:56 +0000 Commit: Kirk McKusick <mckusick@FreeBSD.org> CommitDate: 2023-03-07 23:02:19 +0000 Updates to UFS/FFS superblock integrity checks when reading a superblock. 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 --- sys/ufs/ffs/ffs_subr.c | 38 ++++++++++++++++++++++++++++---------- 1 file changed, 28 insertions(+), 10 deletions(-) diff --git a/sys/ufs/ffs/ffs_subr.c b/sys/ufs/ffs/ffs_subr.c index 0b462add0d05..1d4d98fcb67d 100644 --- a/sys/ufs/ffs/ffs_subr.c +++ b/sys/ufs/ffs/ffs_subr.c @@ -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.