In the Linux kernel, the following vulnerability has been resolved:
net/xen-netback: prevent UAF in xenvif_flush_hash()
During the list_for_each_entry_rcu iteration call of xenvif_flush_hash,
kfree_rcu does not exist inside the rcu read critical section, so if
kfree_rcu is called when the rcu grace period ends during the iteration,
UAF occurs when accessing head->next after the entry becomes free.
Therefore, to solve this, you need to change it to list_for_each_entry_safe.
In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: Set correct chandef when starting CAC
When starting CAC in a mode other than AP mode, it return a
"WARNING: CPU: 0 PID: 63 at cfg80211_chandef_dfs_usable+0x20/0xaf [cfg80211]"
caused by the chandef.chan being null at the end of CAC.
Solution: Ensure the channel definition is set for the different modes
when starting CAC to avoid getting a NULL 'chan' at the end of CAC.
Call Trace:
? show_regs.part.0+0x14/0x16
? __warn+0x67/0xc0
? cfg80211_chandef_dfs_usable+0x20/0xaf [cfg80211]
? report_bug+0xa7/0x130
? exc_overflow+0x30/0x30
? handle_bug+0x27/0x50
? exc_invalid_op+0x18/0x60
? handle_exception+0xf6/0xf6
? exc_overflow+0x30/0x30
? cfg80211_chandef_dfs_usable+0x20/0xaf [cfg80211]
? exc_overflow+0x30/0x30
? cfg80211_chandef_dfs_usable+0x20/0xaf [cfg80211]
? regulatory_propagate_dfs_state.cold+0x1b/0x4c [cfg80211]
? cfg80211_propagate_cac_done_wk+0x1a/0x30 [cfg80211]
? process_one_work+0x165/0x280
? worker_thread+0x120/0x3f0
? kthread+0xc2/0xf0
? process_one_work+0x280/0x280
? kthread_complete_and_exit+0x20/0x20
? ret_from_fork+0x19/0x24
[shorten subject, remove OCB, reorder cases to match previous list]
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath9k_htc: Use __skb_set_length() for resetting urb before resubmit
Syzbot points out that skb_trim() has a sanity check on the existing length of
the skb, which can be uninitialised in some error paths. The intent here is
clearly just to reset the length to zero before resubmitting, so switch to
calling __skb_set_length(skb, 0) directly. In addition, __skb_set_length()
already contains a call to skb_reset_tail_pointer(), so remove the redundant
call.
The syzbot report came from ath9k_hif_usb_reg_in_cb(), but there's a similar
usage of skb_trim() in ath9k_hif_usb_rx_cb(), change both while we're at it.
In the Linux kernel, the following vulnerability has been resolved:
l2tp: prevent possible tunnel refcount underflow
When a session is created, it sets a backpointer to its tunnel. When
the session refcount drops to 0, l2tp_session_free drops the tunnel
refcount if session->tunnel is non-NULL. However, session->tunnel is
set in l2tp_session_create, before the tunnel refcount is incremented
by l2tp_session_register, which leaves a small window where
session->tunnel is non-NULL when the tunnel refcount hasn't been
bumped.
Moving the assignment to l2tp_session_register is trivial but
l2tp_session_create calls l2tp_session_set_header_len which uses
session->tunnel to get the tunnel's encap. Add an encap arg to
l2tp_session_set_header_len to avoid using session->tunnel.
If l2tpv3 sessions have colliding IDs, it is possible for
l2tp_v3_session_get to race with l2tp_session_register and fetch a
session which doesn't yet have session->tunnel set. Add a check for
this case.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Add null check for head_pipe in dcn32_acquire_idle_pipe_for_head_pipe_in_layer
This commit addresses a potential null pointer dereference issue in the
`dcn32_acquire_idle_pipe_for_head_pipe_in_layer` function. The issue
could occur when `head_pipe` is null.
The fix adds a check to ensure `head_pipe` is not null before asserting
it. If `head_pipe` is null, the function returns NULL to prevent a
potential null pointer dereference.
Reported by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn32/dcn32_resource.c:2690 dcn32_acquire_idle_pipe_for_head_pipe_in_layer() error: we previously assumed 'head_pipe' could be null (see line 2681)
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Add null check for head_pipe in dcn201_acquire_free_pipe_for_layer
This commit addresses a potential null pointer dereference issue in the
`dcn201_acquire_free_pipe_for_layer` function. The issue could occur
when `head_pipe` is null.
The fix adds a check to ensure `head_pipe` is not null before asserting
it. If `head_pipe` is null, the function returns NULL to prevent a
potential null pointer dereference.
Reported by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn201/dcn201_resource.c:1016 dcn201_acquire_free_pipe_for_layer() error: we previously assumed 'head_pipe' could be null (see line 1010)
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Check null pointers before multiple uses
[WHAT & HOW]
Poniters, such as stream_enc and dc->bw_vbios, are null checked previously
in the same function, so Coverity warns "implies that stream_enc and
dc->bw_vbios might be null". They are used multiple times in the
subsequent code and need to be checked.
This fixes 10 FORWARD_NULL issues reported by Coverity.