In the Linux kernel, the following vulnerability has been resolved:
usb: dwc3: ep0: fix NULL pointer exception
There is no validation of the index from dwc3_wIndex_to_dep() and we might
be referring a non-existing ep and trigger a NULL pointer exception. In
certain configurations we might use fewer eps and the index might wrongly
indicate a larger ep index than existing.
By adding this validation from the patch we can actually report a wrong
index back to the caller.
In our usecase we are using a composite device on an older kernel, but
upstream might use this fix also. Unfortunately, I cannot describe the
hardware for others to reproduce the issue as it is a proprietary
implementation.
[ 82.958261] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a4
[ 82.966891] Mem abort info:
[ 82.969663] ESR = 0x96000006
[ 82.972703] Exception class = DABT (current EL), IL = 32 bits
[ 82.978603] SET = 0, FnV = 0
[ 82.981642] EA = 0, S1PTW = 0
[ 82.984765] Data abort info:
[ 82.987631] ISV = 0, ISS = 0x00000006
[ 82.991449] CM = 0, WnR = 0
[ 82.994409] user pgtable: 4k pages, 39-bit VAs, pgdp = 00000000c6210ccc
[ 83.000999] [00000000000000a4] pgd=0000000053aa5003, pud=0000000053aa5003, pmd=0000000000000000
[ 83.009685] Internal error: Oops: 96000006 [#1] PREEMPT SMP
[ 83.026433] Process irq/62-dwc3 (pid: 303, stack limit = 0x000000003985154c)
[ 83.033470] CPU: 0 PID: 303 Comm: irq/62-dwc3 Not tainted 4.19.124 #1
[ 83.044836] pstate: 60000085 (nZCv daIf -PAN -UAO)
[ 83.049628] pc : dwc3_ep0_handle_feature+0x414/0x43c
[ 83.054558] lr : dwc3_ep0_interrupt+0x3b4/0xc94
...
[ 83.141788] Call trace:
[ 83.144227] dwc3_ep0_handle_feature+0x414/0x43c
[ 83.148823] dwc3_ep0_interrupt+0x3b4/0xc94
[ 83.181546] ---[ end trace aac6b5267d84c32f ]---
In the Linux kernel, the following vulnerability has been resolved:
bcache: avoid oversized read request in cache missing code path
In the cache missing code path of cached device, if a proper location
from the internal B+ tree is matched for a cache miss range, function
cached_dev_cache_miss() will be called in cache_lookup_fn() in the
following code block,
[code block 1]
526 unsigned int sectors = KEY_INODE(k) == s->iop.inode
527 ? min_t(uint64_t, INT_MAX,
528 KEY_START(k) - bio->bi_iter.bi_sector)
529 : INT_MAX;
530 int ret = s->d->cache_miss(b, s, bio, sectors);
Here s->d->cache_miss() is the call backfunction pointer initialized as
cached_dev_cache_miss(), the last parameter 'sectors' is an important
hint to calculate the size of read request to backing device of the
missing cache data.
Current calculation in above code block may generate oversized value of
'sectors', which consequently may trigger 2 different potential kernel
panics by BUG() or BUG_ON() as listed below,
1) BUG_ON() inside bch_btree_insert_key(),
[code block 2]
886 BUG_ON(b->ops->is_extents && !KEY_SIZE(k));
2) BUG() inside biovec_slab(),
[code block 3]
51 default:
52 BUG();
53 return NULL;
All the above panics are original from cached_dev_cache_miss() by the
oversized parameter 'sectors'.
Inside cached_dev_cache_miss(), parameter 'sectors' is used to calculate
the size of data read from backing device for the cache missing. This
size is stored in s->insert_bio_sectors by the following lines of code,
[code block 4]
909 s->insert_bio_sectors = min(sectors, bio_sectors(bio) + reada);
Then the actual key inserting to the internal B+ tree is generated and
stored in s->iop.replace_key by the following lines of code,
[code block 5]
911 s->iop.replace_key = KEY(s->iop.inode,
912 bio->bi_iter.bi_sector + s->insert_bio_sectors,
913 s->insert_bio_sectors);
The oversized parameter 'sectors' may trigger panic 1) by BUG_ON() from
the above code block.
And the bio sending to backing device for the missing data is allocated
with hint from s->insert_bio_sectors by the following lines of code,
[code block 6]
926 cache_bio = bio_alloc_bioset(GFP_NOWAIT,
927 DIV_ROUND_UP(s->insert_bio_sectors, PAGE_SECTORS),
928 &dc->disk.bio_split);
The oversized parameter 'sectors' may trigger panic 2) by BUG() from the
agove code block.
Now let me explain how the panics happen with the oversized 'sectors'.
In code block 5, replace_key is generated by macro KEY(). From the
definition of macro KEY(),
[code block 7]
71 #define KEY(inode, offset, size) \
72 ((struct bkey) { \
73 .high = (1ULL << 63) | ((__u64) (size) << 20) | (inode), \
74 .low = (offset) \
75 })
Here 'size' is 16bits width embedded in 64bits member 'high' of struct
bkey. But in code block 1, if "KEY_START(k) - bio->bi_iter.bi_sector" is
very probably to be larger than (1<<16) - 1, which makes the bkey size
calculation in code block 5 is overflowed. In one bug report the value
of parameter 'sectors' is 131072 (= 1 << 17), the overflowed 'sectors'
results the overflowed s->insert_bio_sectors in code block 4, then makes
size field of s->iop.replace_key to be 0 in code block 5. Then the 0-
sized s->iop.replace_key is inserted into the internal B+ tree as cache
missing check key (a special key to detect and avoid a racing between
normal write request and cache missing read request) as,
[code block 8]
915 ret = bch_btree_insert_check_key(b, &s->op, &s->iop.replace_key);
Then the 0-sized s->iop.replace_key as 3rd parameter triggers the bkey
size check BUG_ON() in code block 2, and causes the kernel panic 1).
Another ke
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix potential memory leak in DMUB hw_init
[Why]
On resume we perform DMUB hw_init which allocates memory:
dm_resume->dm_dmub_hw_init->dc_dmub_srv_create->kzalloc
That results in memory leak in suspend/resume scenarios.
[How]
Allocate memory for the DC wrapper to DMUB only if it was not
allocated before.
No need to reallocate it on suspend/resume.
In the Linux kernel, the following vulnerability has been resolved:
gfs2: Fix use-after-free in gfs2_glock_shrink_scan
The GLF_LRU flag is checked under lru_lock in gfs2_glock_remove_from_lru() to
remove the glock from the lru list in __gfs2_glock_put().
On the shrink scan path, the same flag is cleared under lru_lock but because
of cond_resched_lock(&lru_lock) in gfs2_dispose_glock_lru(), progress on the
put side can be made without deleting the glock from the lru list.
Keep GLF_LRU across the race window opened by cond_resched_lock(&lru_lock) to
ensure correct behavior on both sides - clear GLF_LRU after list_del under
lru_lock.
In the Linux kernel, the following vulnerability has been resolved:
net: ieee802154: fix null deref in parse dev addr
Fix a logic error that could result in a null deref if the user sets
the mode incorrectly for the given addr type.
In the Linux kernel, the following vulnerability has been resolved:
scsi: core: Fix error handling of scsi_host_alloc()
After device is initialized via device_initialize(), or its name is set via
dev_set_name(), the device has to be freed via put_device(). Otherwise
device name will be leaked because it is allocated dynamically in
dev_set_name().
Fix the leak by replacing kfree() with put_device(). Since
scsi_host_dev_release() properly handles IDA and kthread removal, remove
special-casing these from the error handling as well.
In the Linux kernel, the following vulnerability has been resolved:
PCI: aardvark: Fix kernel panic during PIO transfer
Trying to start a new PIO transfer by writing value 0 in PIO_START register
when previous transfer has not yet completed (which is indicated by value 1
in PIO_START) causes an External Abort on CPU, which results in kernel
panic:
SError Interrupt on CPU0, code 0xbf000002 -- SError
Kernel panic - not syncing: Asynchronous SError Interrupt
To prevent kernel panic, it is required to reject a new PIO transfer when
previous one has not finished yet.
If previous PIO transfer is not finished yet, the kernel may issue a new
PIO request only if the previous PIO transfer timed out.
In the past the root cause of this issue was incorrectly identified (as it
often happens during link retraining or after link down event) and special
hack was implemented in Trusted Firmware to catch all SError events in EL3,
to ignore errors with code 0xbf000002 and not forwarding any other errors
to kernel and instead throw panic from EL3 Trusted Firmware handler.
Links to discussion and patches about this issue:
https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/commit/?id=3c7dcdac5c50
https://lore.kernel.org/linux-pci/20190316161243.29517-1-repk@triplefau.lt/
https://lore.kernel.org/linux-pci/971be151d24312cc533989a64bd454b4@www.loen.fr/
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/1541
But the real cause was the fact that during link retraining or after link
down event the PIO transfer may take longer time, up to the 1.44s until it
times out. This increased probability that a new PIO transfer would be
issued by kernel while previous one has not finished yet.
After applying this change into the kernel, it is possible to revert the
mentioned TF-A hack and SError events do not have to be caught in TF-A EL3.
In the Linux kernel, the following vulnerability has been resolved:
regulator: rt4801: Fix NULL pointer dereference if priv->enable_gpios is NULL
devm_gpiod_get_array_optional may return NULL if no GPIO was assigned.
In the Linux kernel, the following vulnerability has been resolved:
phy: phy-mtk-tphy: Fix some resource leaks in mtk_phy_init()
Use clk_disable_unprepare() in the error path of mtk_phy_init() to fix
some resource leaks.