In the Linux kernel, the following vulnerability has been resolved:
ubi: ubi_wl_put_peb: Fix infinite loop when wear-leveling work failed
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].
In the Linux kernel, the following vulnerability has been resolved:
iommu: Fix error unwind in iommu_group_alloc()
If either iommu_group_grate_file() fails then the
iommu_group is leaked.
Destroy it on these error paths.
Found by kselftest/iommu/iommufd_fail_nth
In the Linux kernel, the following vulnerability has been resolved:
iw_cxgb4: Fix potential NULL dereference in c4iw_fill_res_cm_id_entry()
This condition needs to match the previous "if (epcp->state == LISTEN) {"
exactly to avoid a NULL dereference of either "listen_ep" or "ep". The
problem is that "epcp" has been re-assigned so just testing
"if (epcp->state == LISTEN) {" a second time is not sufficient.
In the Linux kernel, the following vulnerability has been resolved:
FS: JFS: Fix null-ptr-deref Read in txBegin
Syzkaller reported an issue where txBegin may be called
on a superblock in a read-only mounted filesystem which leads
to NULL pointer deref. This could be solved by checking if
the filesystem is read-only before calling txBegin, and returning
with appropiate error code.
In the Linux kernel, the following vulnerability has been resolved:
media: cx23885: Fix a null-ptr-deref bug in buffer_prepare() and buffer_finish()
When the driver calls cx23885_risc_buffer() to prepare the buffer, the
function call dma_alloc_coherent may fail, resulting in a empty buffer
risc->cpu. Later when we free the buffer or access the buffer, null ptr
deref is triggered.
This bug is similar to the following one:
https://git.linuxtv.org/media_stage.git/commit/?id=2b064d91440b33fba5b452f2d1b31f13ae911d71.
We believe the bug can be also dynamically triggered from user side.
Similarly, we fix this by checking the return value of cx23885_risc_buffer()
and the value of risc->cpu before buffer free.
In the Linux kernel, the following vulnerability has been resolved:
scsi: qla4xxx: Add length check when parsing nlattrs
There are three places that qla4xxx parses nlattrs:
- qla4xxx_set_chap_entry()
- qla4xxx_iface_set_param()
- qla4xxx_sysfs_ddb_set_param()
and each of them directly converts the nlattr to specific pointer of
structure without length checking. This could be dangerous as those
attributes are not validated and a malformed nlattr (e.g., length 0) could
result in an OOB read that leaks heap dirty data.
Add the nla_len check before accessing the nlattr data and return EINVAL if
the length check fails.
In the Linux kernel, the following vulnerability has been resolved:
scsi: qla2xxx: Fix potential NULL pointer dereference
Klocwork tool reported 'cur_dsd' may be dereferenced. Add fix to validate
pointer before dereferencing the pointer.