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authorVinit Agnihotri <vinit.agnihotri@gmail.com>2007-07-10 13:04:59 +0300
committerArtem Bityutskiy <Artem.Bityutskiy@nokia.com>2007-07-18 16:58:12 +0300
commitd08c3b78b8c46a01b8fa59037a0d9fbb777fb465 (patch)
treec27d7d436864175107fe8e2b1de3a11b928c975a /drivers/mtd
parent2f3cdb55eef4fa1398965e893f731fb6e6312d34 (diff)
downloadblackbird-op-linux-d08c3b78b8c46a01b8fa59037a0d9fbb777fb465.tar.gz
blackbird-op-linux-d08c3b78b8c46a01b8fa59037a0d9fbb777fb465.zip
UBI: fix overflow bug
I was experiencing overflows in multiplications for volume->used_bytes in vmt.c & vtbl.c, while creating & resizing large volumes. vol->used_bytes is long long however its 2 operands vol->used_ebs & vol->usable_leb_size are int. So their multiplication for larger values causes integer overflows. Typecasting them solves the problem. My machine & flash details: 64Bit dual-core AMD opteron, 1 GB RAM, linux 2.6.18.3. mtd size = 6GB, volume size= 5GB, peb_size = 4MB. heres patch which does the fix. Signed-off-by: Vinit Agnihotri <vinit.agnihotri@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/ubi/vmt.c8
-rw-r--r--drivers/mtd/ubi/vtbl.c9
2 files changed, 11 insertions, 6 deletions
diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
index d62dac90e108..ea0d5c825ab4 100644
--- a/drivers/mtd/ubi/vmt.c
+++ b/drivers/mtd/ubi/vmt.c
@@ -280,7 +280,8 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
vol->used_ebs = vol->reserved_pebs;
vol->last_eb_bytes = vol->usable_leb_size;
- vol->used_bytes = vol->used_ebs * vol->usable_leb_size;
+ vol->used_bytes =
+ (long long)vol->used_ebs * vol->usable_leb_size;
} else {
bytes = vol->used_bytes;
vol->last_eb_bytes = do_div(bytes, vol->usable_leb_size);
@@ -538,7 +539,8 @@ int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs)
if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
vol->used_ebs = reserved_pebs;
vol->last_eb_bytes = vol->usable_leb_size;
- vol->used_bytes = vol->used_ebs * vol->usable_leb_size;
+ vol->used_bytes =
+ (long long)vol->used_ebs * vol->usable_leb_size;
}
paranoid_check_volumes(ubi);
@@ -739,7 +741,7 @@ static void paranoid_check_volume(struct ubi_device *ubi, int vol_id)
goto fail;
}
- n = vol->used_ebs * vol->usable_leb_size;
+ n = (long long)vol->used_ebs * vol->usable_leb_size;
if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
if (vol->corrupted != 0) {
ubi_err("corrupted dynamic volume");
diff --git a/drivers/mtd/ubi/vtbl.c b/drivers/mtd/ubi/vtbl.c
index 1f48c76cf6fe..bc5df50813d6 100644
--- a/drivers/mtd/ubi/vtbl.c
+++ b/drivers/mtd/ubi/vtbl.c
@@ -531,7 +531,8 @@ static int init_volumes(struct ubi_device *ubi, const struct ubi_scan_info *si,
if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
vol->used_ebs = vol->reserved_pebs;
vol->last_eb_bytes = vol->usable_leb_size;
- vol->used_bytes = vol->used_ebs * vol->usable_leb_size;
+ vol->used_bytes =
+ (long long)vol->used_ebs * vol->usable_leb_size;
continue;
}
@@ -561,7 +562,8 @@ static int init_volumes(struct ubi_device *ubi, const struct ubi_scan_info *si,
}
vol->used_ebs = sv->used_ebs;
- vol->used_bytes = (vol->used_ebs - 1) * vol->usable_leb_size;
+ vol->used_bytes =
+ (long long)(vol->used_ebs - 1) * vol->usable_leb_size;
vol->used_bytes += sv->last_data_size;
vol->last_eb_bytes = sv->last_data_size;
}
@@ -578,7 +580,8 @@ static int init_volumes(struct ubi_device *ubi, const struct ubi_scan_info *si,
vol->usable_leb_size = ubi->leb_size;
vol->used_ebs = vol->reserved_pebs;
vol->last_eb_bytes = vol->reserved_pebs;
- vol->used_bytes = vol->used_ebs * (ubi->leb_size - vol->data_pad);
+ vol->used_bytes =
+ (long long)vol->used_ebs * (ubi->leb_size - vol->data_pad);
vol->vol_id = UBI_LAYOUT_VOL_ID;
ubi_assert(!ubi->volumes[i]);
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