In the Linux kernel, the following vulnerability has been resolved:
powerpc: Don't try to copy PPR for task with NULL pt_regs
powerpc sets up PF_KTHREAD and PF_IO_WORKER with a NULL pt_regs, which
from my (arguably very short) checking is not commonly done for other
archs. This is fine, except when PF_IO_WORKER's have been created and
the task does something that causes a coredump to be generated. Then we
get this crash:
Kernel attempted to read user page (160) - exploit attempt? (uid: 1000)
BUG: Kernel NULL pointer dereference on read at 0x00000160
Faulting instruction address: 0xc0000000000c3a60
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=32 NUMA pSeries
Modules linked in: bochs drm_vram_helper drm_kms_helper xts binfmt_misc ecb ctr syscopyarea sysfillrect cbc sysimgblt drm_ttm_helper aes_generic ttm sg libaes evdev joydev virtio_balloon vmx_crypto gf128mul drm dm_mod fuse loop configfs drm_panel_orientation_quirks ip_tables x_tables autofs4 hid_generic usbhid hid xhci_pci xhci_hcd usbcore usb_common sd_mod
CPU: 1 PID: 1982 Comm: ppc-crash Not tainted 6.3.0-rc2+ #88
Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries
NIP: c0000000000c3a60 LR: c000000000039944 CTR: c0000000000398e0
REGS: c0000000041833b0 TRAP: 0300 Not tainted (6.3.0-rc2+)
MSR: 800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 88082828 XER: 200400f8
...
NIP memcpy_power7+0x200/0x7d0
LR ppr_get+0x64/0xb0
Call Trace:
ppr_get+0x40/0xb0 (unreliable)
__regset_get+0x180/0x1f0
regset_get_alloc+0x64/0x90
elf_core_dump+0xb98/0x1b60
do_coredump+0x1c34/0x24a0
get_signal+0x71c/0x1410
do_notify_resume+0x140/0x6f0
interrupt_exit_user_prepare_main+0x29c/0x320
interrupt_exit_user_prepare+0x6c/0xa0
interrupt_return_srr_user+0x8/0x138
Because ppr_get() is trying to copy from a PF_IO_WORKER with a NULL
pt_regs.
Check for a valid pt_regs in both ppc_get/ppr_set, and return an error
if not set. The actual error value doesn't seem to be important here, so
just pick -EINVAL.
[mpe: Trim oops in change log, add Fixes & Cc stable]
In the Linux kernel, the following vulnerability has been resolved:
fbdev/ep93xx-fb: Do not assign to struct fb_info.dev
Do not assing the Linux device to struct fb_info.dev. The call to
register_framebuffer() initializes the field to the fbdev device.
Drivers should not override its value.
Fixes a bug where the driver incorrectly decreases the hardware
device's reference counter and leaks the fbdev device.
v2:
* add Fixes tag (Dan)
In the Linux kernel, the following vulnerability has been resolved:
scsi: target: iscsi: Fix a race condition between login_work and the login thread
In case a malicious initiator sends some random data immediately after a
login PDU; the iscsi_target_sk_data_ready() callback will schedule the
login_work and, at the same time, the negotiation may end without clearing
the LOGIN_FLAGS_INITIAL_PDU flag (because no additional PDU exchanges are
required to complete the login).
The login has been completed but the login_work function will find the
LOGIN_FLAGS_INITIAL_PDU flag set and will never stop from rescheduling
itself; at this point, if the initiator drops the connection, the
iscsit_conn structure will be freed, login_work will dereference a released
socket structure and the kernel crashes.
BUG: kernel NULL pointer dereference, address: 0000000000000230
PF: supervisor write access in kernel mode
PF: error_code(0x0002) - not-present page
Workqueue: events iscsi_target_do_login_rx [iscsi_target_mod]
RIP: 0010:_raw_read_lock_bh+0x15/0x30
Call trace:
iscsi_target_do_login_rx+0x75/0x3f0 [iscsi_target_mod]
process_one_work+0x1e8/0x3c0
Fix this bug by forcing login_work to stop after the login has been
completed and the socket callbacks have been restored.
Add a comment to clearify the return values of iscsi_target_do_login()
In the Linux kernel, the following vulnerability has been resolved:
media: vimc: Fix wrong function called when vimc_init() fails
In vimc_init(), when platform_driver_register(&vimc_pdrv) fails,
platform_driver_unregister(&vimc_pdrv) is wrongly called rather than
platform_device_unregister(&vimc_pdev), which causes kernel warning:
Unexpected driver unregister!
WARNING: CPU: 1 PID: 14517 at drivers/base/driver.c:270 driver_unregister+0x8f/0xb0
RIP: 0010:driver_unregister+0x8f/0xb0
Call Trace:
<TASK>
vimc_init+0x7d/0x1000 [vimc]
do_one_initcall+0xd0/0x4e0
do_init_module+0x1cf/0x6b0
load_module+0x65c2/0x7820
In the Linux kernel, the following vulnerability has been resolved:
cifs: fix oops during encryption
When running xfstests against Azure the following oops occurred on an
arm64 system
Unable to handle kernel write to read-only memory at virtual address
ffff0001221cf000
Mem abort info:
ESR = 0x9600004f
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x0f: level 3 permission fault
Data abort info:
ISV = 0, ISS = 0x0000004f
CM = 0, WnR = 1
swapper pgtable: 4k pages, 48-bit VAs, pgdp=00000000294f3000
[ffff0001221cf000] pgd=18000001ffff8003, p4d=18000001ffff8003,
pud=18000001ff82e003, pmd=18000001ff71d003, pte=00600001221cf787
Internal error: Oops: 9600004f [#1] PREEMPT SMP
...
pstate: 80000005 (Nzcv daif -PAN -UAO -TCO BTYPE=--)
pc : __memcpy+0x40/0x230
lr : scatterwalk_copychunks+0xe0/0x200
sp : ffff800014e92de0
x29: ffff800014e92de0 x28: ffff000114f9de80 x27: 0000000000000008
x26: 0000000000000008 x25: ffff800014e92e78 x24: 0000000000000008
x23: 0000000000000001 x22: 0000040000000000 x21: ffff000000000000
x20: 0000000000000001 x19: ffff0001037c4488 x18: 0000000000000014
x17: 235e1c0d6efa9661 x16: a435f9576b6edd6c x15: 0000000000000058
x14: 0000000000000001 x13: 0000000000000008 x12: ffff000114f2e590
x11: ffffffffffffffff x10: 0000040000000000 x9 : ffff8000105c3580
x8 : 2e9413b10000001a x7 : 534b4410fb86b005 x6 : 534b4410fb86b005
x5 : ffff0001221cf008 x4 : ffff0001037c4490 x3 : 0000000000000001
x2 : 0000000000000008 x1 : ffff0001037c4488 x0 : ffff0001221cf000
Call trace:
__memcpy+0x40/0x230
scatterwalk_map_and_copy+0x98/0x100
crypto_ccm_encrypt+0x150/0x180
crypto_aead_encrypt+0x2c/0x40
crypt_message+0x750/0x880
smb3_init_transform_rq+0x298/0x340
smb_send_rqst.part.11+0xd8/0x180
smb_send_rqst+0x3c/0x100
compound_send_recv+0x534/0xbc0
smb2_query_info_compound+0x32c/0x440
smb2_set_ea+0x438/0x4c0
cifs_xattr_set+0x5d4/0x7c0
This is because in scatterwalk_copychunks(), we attempted to write to
a buffer (@sign) that was allocated in the stack (vmalloc area) by
crypt_message() and thus accessing its remaining 8 (x2) bytes ended up
crossing a page boundary.
To simply fix it, we could just pass @sign kmalloc'd from
crypt_message() and then we're done. Luckily, we don't seem to pass
any other vmalloc'd buffers in smb_rqst::rq_iov...
Instead, let's map the correct pages and offsets from vmalloc buffers
as well in cifs_sg_set_buf() and then avoiding such oopses.
In the Linux kernel, the following vulnerability has been resolved:
trace/fgraph: Fix the warning caused by missing unregister notifier
This warning was triggered during testing on v6.16:
notifier callback ftrace_suspend_notifier_call already registered
WARNING: CPU: 2 PID: 86 at kernel/notifier.c:23 notifier_chain_register+0x44/0xb0
...
Call Trace:
<TASK>
blocking_notifier_chain_register+0x34/0x60
register_ftrace_graph+0x330/0x410
ftrace_profile_write+0x1e9/0x340
vfs_write+0xf8/0x420
? filp_flush+0x8a/0xa0
? filp_close+0x1f/0x30
? do_dup2+0xaf/0x160
ksys_write+0x65/0xe0
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x77/0x7f
When writing to the function_profile_enabled interface, the notifier was
not unregistered after start_graph_tracing failed, causing a warning the
next time function_profile_enabled was written.
Fixed by adding unregister_pm_notifier in the exception path.
In the Linux kernel, the following vulnerability has been resolved:
net: rose: convert 'use' field to refcount_t
The 'use' field in struct rose_neigh is used as a reference counter but
lacks atomicity. This can lead to race conditions where a rose_neigh
structure is freed while still being referenced by other code paths.
For example, when rose_neigh->use becomes zero during an ioctl operation
via rose_rt_ioctl(), the structure may be removed while its timer is
still active, potentially causing use-after-free issues.
This patch changes the type of 'use' from unsigned short to refcount_t and
updates all code paths to use rose_neigh_hold() and rose_neigh_put() which
operate reference counts atomically.