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Merged
merged 1 commit into from
Jul 2, 2021
Merged

rust: add a Task abstraction. #410

merged 1 commit into from
Jul 2, 2021

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wedsonaf
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@wedsonaf wedsonaf commented Jul 1, 2021

This allows users of the kernel crate to get tasks (e.g., the current
task), access their properties (e.g., pid, group_leader, etc.), and hold
on to them if desired. When holding on to tasks, the reference count is
automatically incremented and decremented.

Signed-off-by: Wedson Almeida Filho [email protected]

@ksquirrel

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This allows users of the `kernel` crate to get tasks (e.g., the current
task), access their properties (e.g., pid, group_leader, etc.), and hold
on to them if desired. When holding on to tasks, the reference count is
automatically incremented and decremented.

Signed-off-by: Wedson Almeida Filho <[email protected]>
@ksquirrel
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Review of 6556b37a7fc5:

  • ✔️ Commit 6556b37: Looks fine!

@wedsonaf
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wedsonaf commented Jul 1, 2021

Folks, thank you for the prompt reviews! Very much appreciated.

v1 -> v2

  • Renamed rust_helper_current to rust_helper_get_current.
  • Replaced pid with PID in comments.
  • Removed spurious n from comment.
  • Marked Task Sync as well.
  • Fixed typo in TaskRef description (the -> to).
  • Dropped the use of Cell to create a non-send phantom variable, using (&'a (), *mut ()) now.
  • Removed brackets around struct task_struct in the descriptor of TaskRef::from_ptr

@ojeda ojeda merged commit 5f9ad6c into Rust-for-Linux:rust Jul 2, 2021
@wedsonaf wedsonaf deleted the task branch July 2, 2021 12:17
vtta pushed a commit to vtta/linux-archive that referenced this pull request Sep 29, 2023
When ipv6_vti device is set to the qdisc of the sfb type, the cb field
of the sent skb may be modified during enqueuing. Then,
slab-use-after-free may occur when ipv6_vti device sends IPv6 packets.

The stack information is as follows:
BUG: KASAN: slab-use-after-free in decode_session6+0x103f/0x1890
Read of size 1 at addr ffff88802e08edc2 by task swapper/0/0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.4.0-next-20230707-00001-g84e2cad7f979 Rust-for-Linux#410
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014
Call Trace:
<IRQ>
dump_stack_lvl+0xd9/0x150
print_address_description.constprop.0+0x2c/0x3c0
kasan_report+0x11d/0x130
decode_session6+0x103f/0x1890
__xfrm_decode_session+0x54/0xb0
vti6_tnl_xmit+0x3e6/0x1ee0
dev_hard_start_xmit+0x187/0x700
sch_direct_xmit+0x1a3/0xc30
__qdisc_run+0x510/0x17a0
__dev_queue_xmit+0x2215/0x3b10
neigh_connected_output+0x3c2/0x550
ip6_finish_output2+0x55a/0x1550
ip6_finish_output+0x6b9/0x1270
ip6_output+0x1f1/0x540
ndisc_send_skb+0xa63/0x1890
ndisc_send_rs+0x132/0x6f0
addrconf_rs_timer+0x3f1/0x870
call_timer_fn+0x1a0/0x580
expire_timers+0x29b/0x4b0
run_timer_softirq+0x326/0x910
__do_softirq+0x1d4/0x905
irq_exit_rcu+0xb7/0x120
sysvec_apic_timer_interrupt+0x97/0xc0
</IRQ>
Allocated by task 9176:
kasan_save_stack+0x22/0x40
kasan_set_track+0x25/0x30
__kasan_slab_alloc+0x7f/0x90
kmem_cache_alloc_node+0x1cd/0x410
kmalloc_reserve+0x165/0x270
__alloc_skb+0x129/0x330
netlink_sendmsg+0x9b1/0xe30
sock_sendmsg+0xde/0x190
____sys_sendmsg+0x739/0x920
___sys_sendmsg+0x110/0x1b0
__sys_sendmsg+0xf7/0x1c0
do_syscall_64+0x39/0xb0
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Freed by task 9176:
kasan_save_stack+0x22/0x40
kasan_set_track+0x25/0x30
kasan_save_free_info+0x2b/0x40
____kasan_slab_free+0x160/0x1c0
slab_free_freelist_hook+0x11b/0x220
kmem_cache_free+0xf0/0x490
skb_free_head+0x17f/0x1b0
skb_release_data+0x59c/0x850
consume_skb+0xd2/0x170
netlink_unicast+0x54f/0x7f0
netlink_sendmsg+0x926/0xe30
sock_sendmsg+0xde/0x190
____sys_sendmsg+0x739/0x920
___sys_sendmsg+0x110/0x1b0
__sys_sendmsg+0xf7/0x1c0
do_syscall_64+0x39/0xb0
entry_SYSCALL_64_after_hwframe+0x63/0xcd
The buggy address belongs to the object at ffff88802e08ed00
which belongs to the cache skbuff_small_head of size 640
The buggy address is located 194 bytes inside of
freed 640-byte region [ffff88802e08ed00, ffff88802e08ef80)

As commit f855691 ("xfrm6: Fix the nexthdr offset in
_decode_session6.") showed, xfrm_decode_session was originally intended
only for the receive path. IP6CB(skb)->nhoff is not set during
transmission. Therefore, set the cb field in the skb to 0 before
sending packets.

Fixes: f855691 ("xfrm6: Fix the nexthdr offset in _decode_session6.")
Signed-off-by: Zhengchao Shao <[email protected]>
Signed-off-by: Steffen Klassert <[email protected]>
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5 participants