From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org,
Krzysztof Strasburger <strasbur@chkw386.ch.pwr.wroc.pl>,
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: [ 13/33] fat: fix possible overflow for fat_clusters
Date: Wed, 5 Jun 2013 13:52:51 -0700 [thread overview]
Message-ID: <20130605204705.397162389@linuxfoundation.org> (raw)
In-Reply-To: <20130605204702.359510786@linuxfoundation.org>
3.0-stable review patch. If anyone has any objections, please let me know.
------------------
From: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
commit 7b92d03c3239f43e5b86c9cc9630f026d36ee995 upstream.
Intermediate value of fat_clusters can be overflowed on 32bits arch.
Reported-by: Krzysztof Strasburger <strasbur@chkw386.ch.pwr.wroc.pl>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/fat/inode.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -1236,6 +1236,19 @@ static int fat_read_root(struct inode *i
return 0;
}
+static unsigned long calc_fat_clusters(struct super_block *sb)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+
+ /* Divide first to avoid overflow */
+ if (sbi->fat_bits != 12) {
+ unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits;
+ return ent_per_sec * sbi->fat_length;
+ }
+
+ return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
+}
+
/*
* Read the super block of an MS-DOS FS.
*/
@@ -1433,7 +1446,7 @@ int fat_fill_super(struct super_block *s
sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
/* check that FAT table does not overflow */
- fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
+ fat_clusters = calc_fat_clusters(sb);
total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
if (total_clusters > MAX_FAT(sb)) {
if (!silent)
next prev parent reply other threads:[~2013-06-05 21:00 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-05 20:52 [ 00/33] 3.0.81-stable review Greg Kroah-Hartman
2013-06-05 20:52 ` [ 01/33] avr32: fix relocation check for signed 18-bit offset Greg Kroah-Hartman
2013-06-05 20:52 ` [ 02/33] ARM: plat-orion: Fix num_resources and id for ge10 and ge11 Greg Kroah-Hartman
2013-06-05 20:52 ` [ 03/33] staging: vt6656: use free_netdev instead of kfree Greg Kroah-Hartman
2013-06-05 20:52 ` [ 04/33] usb: option: Add Telewell TW-LTE 4G Greg Kroah-Hartman
2013-06-05 20:52 ` [ 05/33] USB: option: add device IDs for Dell 5804 (Novatel E371) WWAN card Greg Kroah-Hartman
2013-06-05 20:52 ` [ 06/33] USB: ftdi_sio: Add support for Newport CONEX motor drivers Greg Kroah-Hartman
2013-06-05 20:52 ` [ 07/33] USB: cxacru: potential underflow in cxacru_cm_get_array() Greg Kroah-Hartman
2013-06-05 20:52 ` [ 08/33] TTY: Fix tty miss restart after we turn off flow-control Greg Kroah-Hartman
2013-06-05 20:52 ` [ 09/33] USB: Blacklisted Cinterions PLxx WWAN Interface Greg Kroah-Hartman
2013-06-05 20:52 ` [ 10/33] USB: reset resume quirk needed by a hub Greg Kroah-Hartman
2013-06-05 20:52 ` [ 11/33] USB: UHCI: fix for suspend of virtual HP controller Greg Kroah-Hartman
2013-06-05 20:52 ` [ 12/33] cifs: only set ops for inodes in I_NEW state Greg Kroah-Hartman
2013-06-05 20:52 ` Greg Kroah-Hartman [this message]
2013-06-05 20:52 ` [ 14/33] ocfs2: goto out_unlock if ocfs2_get_clusters_nocache() failed in ocfs2_fiemap() Greg Kroah-Hartman
2013-06-05 20:52 ` [ 15/33] Kirkwood: Enable PCIe port 1 on QNAP TS-11x/TS-21x Greg Kroah-Hartman
2013-06-05 20:52 ` [ 16/33] mm compaction: fix of improper cache flush in migration code Greg Kroah-Hartman
2013-06-05 20:52 ` [ 17/33] klist: del waiter from klist_remove_waiters before wakeup waitting process Greg Kroah-Hartman
2013-06-05 20:52 ` [ 18/33] wait: fix false timeouts when using wait_event_timeout() Greg Kroah-Hartman
2013-06-05 20:52 ` [ 19/33] nilfs2: fix issue of nilfs_set_page_dirty() for page at EOF boundary Greg Kroah-Hartman
2013-06-05 20:52 ` [ 20/33] mm: mmu_notifier: re-fix freed page still mapped in secondary MMU Greg Kroah-Hartman
2013-06-05 20:52 ` [ 21/33] drivers/block/brd.c: fix brd_lookup_page() race Greg Kroah-Hartman
2013-06-05 20:53 ` [ 22/33] mm/THP: use pmd_populate() to update the pmd with pgtable_t pointer Greg Kroah-Hartman
2013-06-05 20:53 ` [ 23/33] um: Serve io_remap_pfn_range() Greg Kroah-Hartman
2013-06-05 20:53 ` [ 24/33] drm/radeon: fix card_posted check for newer asics Greg Kroah-Hartman
2013-06-05 20:53 ` [ 25/33] cifs: fix potential buffer overrun when composing a new options string Greg Kroah-Hartman
2013-06-05 20:53 ` [ 26/33] USB: io_ti: Fix NULL dereference in chase_port() Greg Kroah-Hartman
2013-06-05 20:53 ` [ 27/33] libata: make ata_exec_internal_sg honor DMADIR Greg Kroah-Hartman
2013-06-05 20:53 ` [ 28/33] xen/events: Handle VIRQ_TIMER before any other hardirq in event loop Greg Kroah-Hartman
2013-06-05 20:53 ` [ 29/33] jfs: fix a couple races Greg Kroah-Hartman
2013-06-05 20:53 ` [ 30/33] ALSA: usb-audio: fix possible hang and overflow in parse_uac2_sample_rate_range() Greg Kroah-Hartman
2013-06-05 20:53 ` [ 31/33] ALSA: usb-audio: avoid integer overflow in create_fixed_stream_quirk() Greg Kroah-Hartman
2013-06-05 20:53 ` [ 32/33] mac80211: close AP_VLAN interfaces before unregistering all Greg Kroah-Hartman
2013-06-05 20:53 ` [ 33/33] thinkpad-acpi: recognize latest V-Series using DMI_BIOS_VENDOR Greg Kroah-Hartman
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