Commit 5ea45f54 authored by Jonas 'Sortie' Termansen's avatar Jonas 'Sortie' Termansen Committed by Jan Kara
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isofs: fix Y2038 and Y2156 issues in Rock Ridge TF entry 



This change implements the Rock Ridge TF entry LONG_FORM bit, which uses
the ISO 9660 17-byte date format (up to year 9999, with 10ms precision)
instead of the 7-byte date format (up to year 2155, with 1s precision).

Previously the LONG_FORM bit was ignored; and isofs would entirely
misinterpret the date as the wrong format, resulting in garbage
timestamps on the filesystem.

The Y2038 issue in iso_date() is fixed by returning a struct timespec64
instead of an int.

parse_rock_ridge_inode_internal() is fixed so it does proper bounds
checks of the TF entry timestamps.

Signed-off-by: default avatarJonas 'Sortie' Termansen <sortie@maxsi.org>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250411145022.2292255-1-sortie@maxsi.org
parent 0405d4b6

fs/isofs/inode.c

+5 −2
Original line number Diff line number Diff line
@@ -1275,6 +1275,7 @@ static int isofs_read_inode(struct inode *inode, int relocated) 
	unsigned long offset;

	struct iso_inode_info *ei = ISOFS_I(inode);

	int ret = -EIO;

	struct timespec64 ts;



	block = ei->i_iget5_block;

	bh = sb_bread(inode->i_sb, block);
@@ -1387,8 +1388,10 @@ static int isofs_read_inode(struct inode *inode, int relocated) 
			inode->i_ino, de->flags[-high_sierra]);

	}

#endif

	inode_set_mtime_to_ts(inode,

			      inode_set_atime_to_ts(inode, inode_set_ctime(inode, iso_date(de->date, high_sierra), 0)));

	ts = iso_date(de->date, high_sierra ? ISO_DATE_HIGH_SIERRA : 0);

	inode_set_ctime_to_ts(inode, ts);

	inode_set_atime_to_ts(inode, ts);

	inode_set_mtime_to_ts(inode, ts);



	ei->i_first_extent = (isonum_733(de->extent) +

			isonum_711(de->ext_attr_length));

fs/isofs/isofs.h

+3 −1
Original line number Diff line number Diff line
@@ -106,7 +106,9 @@ static inline unsigned int isonum_733(u8 *p) 
	/* Ignore bigendian datum due to broken mastering programs */

	return get_unaligned_le32(p);

}

extern int iso_date(u8 *, int);

#define ISO_DATE_HIGH_SIERRA (1 << 0)

#define ISO_DATE_LONG_FORM (1 << 1)

struct timespec64 iso_date(u8 *p, int flags);



struct inode;		/* To make gcc happy */

fs/isofs/rock.c

+23 −17
Original line number Diff line number Diff line
@@ -412,7 +412,12 @@ parse_rock_ridge_inode_internal(struct iso_directory_record *de, 
				}

			}

			break;

		case SIG('T', 'F'):

		case SIG('T', 'F'): {

			int flags, size, slen;



			flags = rr->u.TF.flags & TF_LONG_FORM ? ISO_DATE_LONG_FORM : 0;

			size = rr->u.TF.flags & TF_LONG_FORM ? 17 : 7;

			slen = rr->len - 5;

			/*

			 * Some RRIP writers incorrectly place ctime in the

			 * TF_CREATE field. Try to handle this correctly for
@@ -420,27 +425,28 @@ parse_rock_ridge_inode_internal(struct iso_directory_record *de, 
			 */

			/* Rock ridge never appears on a High Sierra disk */

			cnt = 0;

			if (rr->u.TF.flags & TF_CREATE) {

				inode_set_ctime(inode,

						iso_date(rr->u.TF.times[cnt++].time, 0),

						0);

			if ((rr->u.TF.flags & TF_CREATE) && size <= slen) {

				inode_set_ctime_to_ts(inode,

						iso_date(rr->u.TF.data + size * cnt++, flags));

				slen -= size;

			}

			if (rr->u.TF.flags & TF_MODIFY) {

				inode_set_mtime(inode,

						iso_date(rr->u.TF.times[cnt++].time, 0),

						0);

			if ((rr->u.TF.flags & TF_MODIFY) && size <= slen) {

				inode_set_mtime_to_ts(inode,

						iso_date(rr->u.TF.data + size * cnt++, flags));

				slen -= size;

			}

			if (rr->u.TF.flags & TF_ACCESS) {

				inode_set_atime(inode,

						iso_date(rr->u.TF.times[cnt++].time, 0),

						0);

			if ((rr->u.TF.flags & TF_ACCESS) && size <= slen) {

				inode_set_atime_to_ts(inode,

						iso_date(rr->u.TF.data + size * cnt++, flags));

				slen -= size;

			}

			if (rr->u.TF.flags & TF_ATTRIBUTES) {

				inode_set_ctime(inode,

						iso_date(rr->u.TF.times[cnt++].time, 0),

						0);

			if ((rr->u.TF.flags & TF_ATTRIBUTES) && size <= slen) {

				inode_set_ctime_to_ts(inode,

						iso_date(rr->u.TF.data + size * cnt++, flags));

				slen -= size;

			}

			break;

		}

		case SIG('S', 'L'):

			{

				int slen;

fs/isofs/rock.h

+1 −5
Original line number Diff line number Diff line
@@ -65,13 +65,9 @@ struct RR_PL_s { 
	__u8 location[8];

};



struct stamp {

	__u8 time[7];		/* actually 6 unsigned, 1 signed */

} __attribute__ ((packed));



struct RR_TF_s {

	__u8 flags;

	struct stamp times[];	/* Variable number of these beasts */

	__u8 data[];

} __attribute__ ((packed));



/* Linux-specific extension for transparent decompression */

fs/isofs/util.c

+32 −17
Original line number Diff line number Diff line
@@ -16,24 +16,39 @@ 
 * to GMT.  Thus  we should always be correct.

 */



int iso_date(u8 *p, int flag)

struct timespec64 iso_date(u8 *p, int flags)

{

	int year, month, day, hour, minute, second, tz;

	int crtime;

	struct timespec64 ts;



	if (flags & ISO_DATE_LONG_FORM) {

		year = (p[0] - '0') * 1000 +

		       (p[1] - '0') * 100 +

		       (p[2] - '0') * 10 +

		       (p[3] - '0') - 1900;

		month = ((p[4] - '0') * 10 + (p[5] - '0'));

		day = ((p[6] - '0') * 10 + (p[7] - '0'));

		hour = ((p[8] - '0') * 10 + (p[9] - '0'));

		minute = ((p[10] - '0') * 10 + (p[11] - '0'));

		second = ((p[12] - '0') * 10 + (p[13] - '0'));

		ts.tv_nsec = ((p[14] - '0') * 10 + (p[15] - '0')) * 10000000;

		tz = p[16];

	} else {

		year = p[0];

		month = p[1];

		day = p[2];

		hour = p[3];

		minute = p[4];

		second = p[5];

	if (flag == 0) tz = p[6]; /* High sierra has no time zone */

	else tz = 0;

		ts.tv_nsec = 0;

		/* High sierra has no time zone */

		tz = flags & ISO_DATE_HIGH_SIERRA ? 0 : p[6];

	}



	if (year < 0) {

		crtime = 0;

		ts.tv_sec = 0;

	} else {

		crtime = mktime64(year+1900, month, day, hour, minute, second);

		ts.tv_sec = mktime64(year+1900, month, day, hour, minute, second);



		/* sign extend */

		if (tz & 0x80)
@@ -65,7 +80,7 @@ int iso_date(u8 *p, int flag) 
		 * for pointing out the sign error.

		 */

		if (-52 <= tz && tz <= 52)

			crtime -= tz * 15 * 60;

			ts.tv_sec -= tz * 15 * 60;

	}

	return crtime;

	return ts;

}