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path: root/fs/exfat/exfat_raw.h
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2021-02-22exfat: fix shift-out-of-bounds in exfat_fill_super()Namjae Jeon
syzbot reported a warning which could cause shift-out-of-bounds issue. Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x183/0x22e lib/dump_stack.c:120 ubsan_epilogue lib/ubsan.c:148 [inline] __ubsan_handle_shift_out_of_bounds+0x432/0x4d0 lib/ubsan.c:395 exfat_read_boot_sector fs/exfat/super.c:471 [inline] __exfat_fill_super fs/exfat/super.c:556 [inline] exfat_fill_super+0x2acb/0x2d00 fs/exfat/super.c:624 get_tree_bdev+0x406/0x630 fs/super.c:1291 vfs_get_tree+0x86/0x270 fs/super.c:1496 do_new_mount fs/namespace.c:2881 [inline] path_mount+0x1937/0x2c50 fs/namespace.c:3211 do_mount fs/namespace.c:3224 [inline] __do_sys_mount fs/namespace.c:3432 [inline] __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3409 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 exfat specification describe sect_per_clus_bits field of boot sector could be at most 25 - sect_size_bits and at least 0. And sect_size_bits can also affect this calculation, It also needs validation. This patch add validation for sect_per_clus_bits and sect_size_bits field of boot sector. Fixes: 719c1e182916 ("exfat: add super block operations") Cc: stable@vger.kernel.org # v5.9+ Reported-by: syzbot+da4fe66aaadd3c2e2d1c@syzkaller.appspotmail.com Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Tested-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-08-12exfat: retain 'VolumeFlags' properlyTetsuhiro Kohada
MediaFailure and VolumeDirty should be retained if these are set before mounting. In '3.1.13.3 Media Failure Field' of exfat specification describe: If, upon mounting a volume, the value of this field is 1, implementations which scan the entire volume for media failures and record all failures as "bad" clusters in the FAT (or otherwise resolve media failures) may clear the value of this field to 0. Therefore, We should not clear MediaFailure without scanning volume. In '8.1 Recommended Write Ordering' of exfat specification describe: Clear the value of the VolumeDirty field to 0, if its value prior to the first step was 0. Therefore, We should not clear VolumeDirty after mounting. Also rename ERR_MEDIUM to MEDIA_FAILURE. Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-09exfat: separate the boot sector analysisTetsuhiro Kohada
Separate the boot sector analysis to read_boot_sector(). And add a check for the fs_name field. Furthermore, add a strict consistency check, because overlapping areas can cause serious corruption. Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-09exfat: redefine PBR as boot_sectorTetsuhiro Kohada
Aggregate PBR related definitions and redefine as "boot_sector" to comply with the exFAT specification. And, rename variable names including 'pbr'. Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-06-09exfat: replace 'time_ms' with 'time_cs'Tetsuhiro Kohada
Replace time_ms with time_cs in the file directory entry structure and related functions. The unit of create_time_ms/modify_time_ms in File Directory Entry are not 'milli-second', but 'centi-second'. The exfat specification uses the term '10ms', but instead use 'cs' as in msdos_fs.h. Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-03-05exfat: add in-memory and on-disk structures and headersNamjae Jeon
This adds in-memory and on-disk structures and headers. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com> Reviewed-by: Pali Rohár <pali.rohar@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>