[ Upstream commit 4d57a7333e26040f2b583983e1970d9d460e56b0 ]
Following process will trigger an infinite loop in ubi_wl_put_peb():
ubifs_bgt ubi_bgt
ubifs_leb_unmap
ubi_leb_unmap
ubi_eba_unmap_leb
ubi_wl_put_peb wear_leveling_worker
e1 = rb_entry(rb_first(&ubi->used)
e2 = get_peb_for_wl(ubi)
ubi_io_read_vid_hdr // return err (flash fault)
out_error:
ubi->move_from = ubi->move_to = NULL
wl_entry_destroy(ubi, e1)
ubi->lookuptbl[e->pnum] = NULL
retry:
e = ubi->lookuptbl[pnum]; // return NULL
if (e == ubi->move_from) { // NULL == NULL gets true
goto retry; // infinite loop !!!
$ top
PID USER PR NI VIRT RES SHR S %CPU %MEM COMMAND
7676 root 20 0 0 0 0 R 100.0 0.0 ubifs_bgt0_0
Fix it by:
1) Letting ubi_wl_put_peb() returns directly if wearl leveling entry has
been removed from 'ubi->lookuptbl'.
2) Using 'ubi->wl_lock' protecting wl entry deletion to preventing an
use-after-free problem for wl entry in ubi_wl_put_peb().
Fetch a reproducer in [Link].
Fixes: 43f9b25a9cdd7b1 ("UBI: bugfix: protect from volume removal")
Fixes: ee59ba8b064f692 ("UBI: Fix stale pointers in ubi->lookuptbl")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216111
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a240bc5c43130c6aa50831d7caaa02a1d84e1bce ]
Wear-leveling entry could be freed in error path, which may be accessed
again in eraseblk_count_seq_show(), for example:
__erase_worker eraseblk_count_seq_show
wl = ubi->lookuptbl[*block_number]
if (wl)
wl_entry_destroy
ubi->lookuptbl[e->pnum] = NULL
kmem_cache_free(ubi_wl_entry_slab, e)
erase_count = wl->ec // UAF!
Wear-leveling entry updating/accessing in ubi->lookuptbl should be
protected by ubi->wl_lock, fix it by adding ubi->wl_lock to serialize
wl entry accessing between wl_entry_destroy() and
eraseblk_count_seq_show().
Fetch a reproducer in [Link].
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216305
Fixes: 7bccd12d27b7e3 ("ubi: Add debugfs file for tracking PEB state")
Fixes: 801c135ce73d5d ("UBI: Unsorted Block Images")
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 76f9476ece445a07aeb72df9d896cd563fb5b50f ]
After disabling fastmap(ubi->fm_disabled = 1), fastmap won't be updated,
fm_anchor PEB is missed being scheduled for erasing. Besides, fm_anchor
PEB may have smallest erase count, it doesn't participate wear-leveling.
The difference of erase count between fm_anchor PEB and other PEBs will
be larger and larger later on.
In which situation fastmap can be disabled? Initially, we have an UBI
image with fastmap. Then the image will be atttached without module
parameter 'fm_autoconvert', ubi turns to full scanning mode in one
random attaching process(eg. bad fastmap caused by powercut), ubi
fastmap is disabled since then.
Fix it by not getting fm_anchor if fastmap is disabled in
ubi_refill_pools().
Fetch a reproducer in [Link].
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216341
Fixes: 4b68bf9a69d22d ("ubi: Select fastmap anchor PEBs considering ...")
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c15859bfd326c10230f09cb48a17f8a35f190342 ]
It willl cause null-ptr-deref in the following case:
uif_init()
ubi_add_volume()
cdev_add() -> if it fails, call kill_volumes()
device_register()
kill_volumes() -> if ubi_add_volume() fails call this function
ubi_free_volume()
cdev_del()
device_unregister() -> trying to delete a not added device,
it causes null-ptr-deref
So in ubi_free_volume(), it delete devices whether they are added
or not, it will causes null-ptr-deref.
Handle the error case whlie calling ubi_add_volume() to fix this
problem. If add volume fails, set the corresponding vol to null,
so it can not be accessed in kill_volumes() and release the
resource in ubi_add_volume() error path.
Fixes: 801c135ce73d ("UBI: Unsorted Block Images")
Suggested-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1e591ea072df7211f64542a09482b5f81cb3ad27 ]
There is a memory leaks problem reported by kmemleak:
unreferenced object 0xffff888102007a00 (size 128):
comm "ubirsvol", pid 32090, jiffies 4298464136 (age 2361.231s)
hex dump (first 32 bytes):
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
backtrace:
[<ffffffff8176cecd>] __kmalloc+0x4d/0x150
[<ffffffffa02a9a36>] ubi_eba_create_table+0x76/0x170 [ubi]
[<ffffffffa029764e>] ubi_resize_volume+0x1be/0xbc0 [ubi]
[<ffffffffa02a3321>] ubi_cdev_ioctl+0x701/0x1850 [ubi]
[<ffffffff81975d2d>] __x64_sys_ioctl+0x11d/0x170
[<ffffffff83c142a5>] do_syscall_64+0x35/0x80
[<ffffffff83e0006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
This is due to a mismatch between create and destroy interfaces, and
in detail that "new_eba_tbl" created by ubi_eba_create_table() but
destroyed by kfree(), while will causing "new_eba_tbl->entries" not
freed.
Fix it by replacing kfree(new_eba_tbl) with
ubi_eba_destroy_table(new_eba_tbl)
Fixes: 799dca34ac54 ("UBI: hide EBA internals")
Signed-off-by: Li Zetao <lizetao1@huawei.com>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9af31d6ec1a4be4caab2550096c6bd2ba8fba472 ]
There is an use-after-free problem reported by KASAN:
==================================================================
BUG: KASAN: use-after-free in ubi_eba_copy_table+0x11f/0x1c0 [ubi]
Read of size 8 at addr ffff888101eec008 by task ubirsvol/4735
CPU: 2 PID: 4735 Comm: ubirsvol
Not tainted 6.1.0-rc1-00003-g84fa3304a7fc-dirty #14
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 1.14.0-1.fc33 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x34/0x44
print_report+0x171/0x472
kasan_report+0xad/0x130
ubi_eba_copy_table+0x11f/0x1c0 [ubi]
ubi_resize_volume+0x4f9/0xbc0 [ubi]
ubi_cdev_ioctl+0x701/0x1850 [ubi]
__x64_sys_ioctl+0x11d/0x170
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
</TASK>
When ubi_change_vtbl_record() returns an error in ubi_resize_volume(),
"new_eba_tbl" will be freed on error handing path, but it is holded
by "vol->eba_tbl" in ubi_eba_replace_table(). It means that the liftcycle
of "vol->eba_tbl" and "vol" are different, so when resizing volume in
next time, it causing an use-after-free fault.
Fix it by not freeing "new_eba_tbl" after it replaced in
ubi_eba_replace_table(), while will be freed in next volume resizing.
Fixes: 801c135ce73d ("UBI: Unsorted Block Images")
Signed-off-by: Li Zetao <lizetao1@huawei.com>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1b42b1a36fc946f0d7088425b90d491b4257ca3e ]
Ensure that the VID header offset + VID header size does not exceed
the allocated area to avoid slab OOB.
BUG: KASAN: slab-out-of-bounds in crc32_body lib/crc32.c:111 [inline]
BUG: KASAN: slab-out-of-bounds in crc32_le_generic lib/crc32.c:179 [inline]
BUG: KASAN: slab-out-of-bounds in crc32_le_base+0x58c/0x626 lib/crc32.c:197
Read of size 4 at addr ffff88802bb36f00 by task syz-executor136/1555
CPU: 2 PID: 1555 Comm: syz-executor136 Tainted: G W
6.0.0-1868 #1
Hardware name: Red Hat KVM, BIOS 1.13.0-2.module+el8.3.0+7860+a7792d29
04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x85/0xad lib/dump_stack.c:106
print_address_description mm/kasan/report.c:317 [inline]
print_report.cold.13+0xb6/0x6bb mm/kasan/report.c:433
kasan_report+0xa7/0x11b mm/kasan/report.c:495
crc32_body lib/crc32.c:111 [inline]
crc32_le_generic lib/crc32.c:179 [inline]
crc32_le_base+0x58c/0x626 lib/crc32.c:197
ubi_io_write_vid_hdr+0x1b7/0x472 drivers/mtd/ubi/io.c:1067
create_vtbl+0x4d5/0x9c4 drivers/mtd/ubi/vtbl.c:317
create_empty_lvol drivers/mtd/ubi/vtbl.c:500 [inline]
ubi_read_volume_table+0x67b/0x288a drivers/mtd/ubi/vtbl.c:812
ubi_attach+0xf34/0x1603 drivers/mtd/ubi/attach.c:1601
ubi_attach_mtd_dev+0x6f3/0x185e drivers/mtd/ubi/build.c:965
ctrl_cdev_ioctl+0x2db/0x347 drivers/mtd/ubi/cdev.c:1043
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x193/0x213 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3e/0x86 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0x0
RIP: 0033:0x7f96d5cf753d
Code:
RSP: 002b:00007fffd72206f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f96d5cf753d
RDX: 0000000020000080 RSI: 0000000040186f40 RDI: 0000000000000003
RBP: 0000000000400cd0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000400be0
R13: 00007fffd72207e0 R14: 0000000000000000 R15: 0000000000000000
</TASK>
Allocated by task 1555:
kasan_save_stack+0x20/0x3d mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:45 [inline]
set_alloc_info mm/kasan/common.c:437 [inline]
____kasan_kmalloc mm/kasan/common.c:516 [inline]
__kasan_kmalloc+0x88/0xa3 mm/kasan/common.c:525
kasan_kmalloc include/linux/kasan.h:234 [inline]
__kmalloc+0x138/0x257 mm/slub.c:4429
kmalloc include/linux/slab.h:605 [inline]
ubi_alloc_vid_buf drivers/mtd/ubi/ubi.h:1093 [inline]
create_vtbl+0xcc/0x9c4 drivers/mtd/ubi/vtbl.c:295
create_empty_lvol drivers/mtd/ubi/vtbl.c:500 [inline]
ubi_read_volume_table+0x67b/0x288a drivers/mtd/ubi/vtbl.c:812
ubi_attach+0xf34/0x1603 drivers/mtd/ubi/attach.c:1601
ubi_attach_mtd_dev+0x6f3/0x185e drivers/mtd/ubi/build.c:965
ctrl_cdev_ioctl+0x2db/0x347 drivers/mtd/ubi/cdev.c:1043
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x193/0x213 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3e/0x86 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0x0
The buggy address belongs to the object at ffff88802bb36e00
which belongs to the cache kmalloc-256 of size 256
The buggy address is located 0 bytes to the right of
256-byte region [ffff88802bb36e00, ffff88802bb36f00)
The buggy address belongs to the physical page:
page:00000000ea4d1263 refcount:1 mapcount:0 mapping:0000000000000000
index:0x0 pfn:0x2bb36
head:00000000ea4d1263 order:1 compound_mapcount:0 compound_pincount:0
flags: 0xfffffc0010200(slab|head|node=0|zone=1|lastcpupid=0x1fffff)
raw: 000fffffc0010200 ffffea000066c300 dead000000000003 ffff888100042b40
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88802bb36e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88802bb36e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88802bb36f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff88802bb36f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88802bb37000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
Fixes: 801c135ce73d ("UBI: Unsorted Block Images")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: George Kennedy <george.kennedy@oracle.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This is a simple mechanical transformation done by: @@ expression E; @@ - prandom_u32_max + get_random_u32_below (E) Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs Reviewed-by: SeongJae Park <sj@kernel.org> # for damon Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Pull more random number generator updates from Jason Donenfeld:
"This time with some large scale treewide cleanups.
The intent of this pull is to clean up the way callers fetch random
integers. The current rules for doing this right are:
- If you want a secure or an insecure random u64, use get_random_u64()
- If you want a secure or an insecure random u32, use get_random_u32()
The old function prandom_u32() has been deprecated for a while
now and is just a wrapper around get_random_u32(). Same for
get_random_int().
- If you want a secure or an insecure random u16, use get_random_u16()
- If you want a secure or an insecure random u8, use get_random_u8()
- If you want secure or insecure random bytes, use get_random_bytes().
The old function prandom_bytes() has been deprecated for a while
now and has long been a wrapper around get_random_bytes()
- If you want a non-uniform random u32, u16, or u8 bounded by a
certain open interval maximum, use prandom_u32_max()
I say "non-uniform", because it doesn't do any rejection sampling
or divisions. Hence, it stays within the prandom_*() namespace, not
the get_random_*() namespace.
I'm currently investigating a "uniform" function for 6.2. We'll see
what comes of that.
By applying these rules uniformly, we get several benefits:
- By using prandom_u32_max() with an upper-bound that the compiler
can prove at compile-time is ≤65536 or ≤256, internally
get_random_u16() or get_random_u8() is used, which wastes fewer
batched random bytes, and hence has higher throughput.
- By using prandom_u32_max() instead of %, when the upper-bound is
not a constant, division is still avoided, because
prandom_u32_max() uses a faster multiplication-based trick instead.
- By using get_random_u16() or get_random_u8() in cases where the
return value is intended to indeed be a u16 or a u8, we waste fewer
batched random bytes, and hence have higher throughput.
This series was originally done by hand while I was on an airplane
without Internet. Later, Kees and I worked on retroactively figuring
out what could be done with Coccinelle and what had to be done
manually, and then we split things up based on that.
So while this touches a lot of files, the actual amount of code that's
hand fiddled is comfortably small"
* tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
prandom: remove unused functions
treewide: use get_random_bytes() when possible
treewide: use get_random_u32() when possible
treewide: use get_random_{u8,u16}() when possible, part 2
treewide: use get_random_{u8,u16}() when possible, part 1
treewide: use prandom_u32_max() when possible, part 2
treewide: use prandom_u32_max() when possible, part 1
Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done mechanically with this coccinelle script:
@basic@
expression E;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u64;
@@
(
- ((T)get_random_u32() % (E))
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ((E) - 1))
+ prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2)
|
- ((u64)(E) * get_random_u32() >> 32)
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ~PAGE_MASK)
+ prandom_u32_max(PAGE_SIZE)
)
@multi_line@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
identifier RAND;
expression E;
@@
- RAND = get_random_u32();
... when != RAND
- RAND %= (E);
+ RAND = prandom_u32_max(E);
// Find a potential literal
@literal_mask@
expression LITERAL;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
position p;
@@
((T)get_random_u32()@p & (LITERAL))
// Add one to the literal.
@script:python add_one@
literal << literal_mask.LITERAL;
RESULT;
@@
value = None
if literal.startswith('0x'):
value = int(literal, 16)
elif literal[0] in '123456789':
value = int(literal, 10)
if value is None:
print("I don't know how to handle %s" % (literal))
cocci.include_match(False)
elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1:
print("Skipping 0x%x for cleanup elsewhere" % (value))
cocci.include_match(False)
elif value & (value + 1) != 0:
print("Skipping 0x%x because it's not a power of two minus one" % (value))
cocci.include_match(False)
elif literal.startswith('0x'):
coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1))
else:
coccinelle.RESULT = cocci.make_expr("%d" % (value + 1))
// Replace the literal mask with the calculated result.
@plus_one@
expression literal_mask.LITERAL;
position literal_mask.p;
expression add_one.RESULT;
identifier FUNC;
@@
- (FUNC()@p & (LITERAL))
+ prandom_u32_max(RESULT)
@collapse_ret@
type T;
identifier VAR;
expression E;
@@
{
- T VAR;
- VAR = (E);
- return VAR;
+ return E;
}
@drop_var@
type T;
identifier VAR;
@@
{
- T VAR;
... when != VAR
}
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: KP Singh <kpsingh@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>