Описание
In the Linux kernel, the following vulnerability has been resolved:
net: dst_metadata: fix false-positive memcpy overflow in tun_dst_unclone
kmalloc_flex() in metadata_dst_alloc() sets __counted_by for the
structure to the options_len, which is then initialized to zero.
Later, we're initializing the structure by copying the tunnel info
together with the options, and this triggers a warning for a potential
memcpy overflow, since the compiler estimates that the options can't
fit into the structure, even though the memory for them is actually
allocated.
memcpy: detected buffer overflow: 104 byte write of buffer size 96
WARNING: CPU: X PID: Y at lib/string_helpers.c:1036 __fortify_report
skb_tunnel_info_unclone+0x179/0x190
geneve_xmit+0x7fe/0xe00
The issue is triggered when built with clang and source fortification.
Fix that by doing the copy in two stages: first - the main data with
the options_len, then the options. This way the correct length should
be known at the time of the copy.
It would be better if the options_len never changed after allocation,
but the allocation code is a little separate from the initialization
and it would be awkward and potentially dangerous to return a struct
with options_len set to a non-zero value from the metadata_dst_alloc().
Another option would be to use ip_tunnel_info_opts_set(), but it is
doing too many unnecessary operations for the use case here.
A flaw was found in the Linux kernel's dst_metadata component. When copying tunnel information and options within the tun_dst_unclone function, a compiler warning for a potential memory buffer overflow is triggered. This warning is a false positive, as memory is correctly allocated, but it can lead to misleading diagnostics.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 6 | kernel | Out of support scope | ||
| Red Hat Enterprise Linux 7 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Fix deferred | ||
| Red Hat OpenShift Container Platform 4 | rhcos | Not affected |
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Дополнительная информация
Статус:
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: net: dst_metadata: fix false-positive memcpy overflow in tun_dst_unclone kmalloc_flex() in metadata_dst_alloc() sets __counted_by for the structure to the options_len, which is then initialized to zero. Later, we're initializing the structure by copying the tunnel info together with the options, and this triggers a warning for a potential memcpy overflow, since the compiler estimates that the options can't fit into the structure, even though the memory for them is actually allocated. memcpy: detected buffer overflow: 104 byte write of buffer size 96 WARNING: CPU: X PID: Y at lib/string_helpers.c:1036 __fortify_report skb_tunnel_info_unclone+0x179/0x190 geneve_xmit+0x7fe/0xe00 The issue is triggered when built with clang and source fortification. Fix that by doing the copy in two stages: first - the main data with the options_len, then the options. This way the correct length should be known at the time of the copy....
In the Linux kernel, the following vulnerability has been resolved: net: dst_metadata: fix false-positive memcpy overflow in tun_dst_unclone kmalloc_flex() in metadata_dst_alloc() sets __counted_by for the structure to the options_len, which is then initialized to zero. Later, we're initializing the structure by copying the tunnel info together with the options, and this triggers a warning for a potential memcpy overflow, since the compiler estimates that the options can't fit into the structure, even though the memory for them is actually allocated. memcpy: detected buffer overflow: 104 byte write of buffer size 96 WARNING: CPU: X PID: Y at lib/string_helpers.c:1036 __fortify_report skb_tunnel_info_unclone+0x179/0x190 geneve_xmit+0x7fe/0xe00 The issue is triggered when built with clang and source fortification. Fix that by doing the copy in two stages: first - the main data with the options_len, then the options. This way the correct length should be known at the time of t
In the Linux kernel, the following vulnerability has been resolved: n ...
In the Linux kernel, the following vulnerability has been resolved: net: dst_metadata: fix false-positive memcpy overflow in tun_dst_unclone kmalloc_flex() in metadata_dst_alloc() sets __counted_by for the structure to the options_len, which is then initialized to zero. Later, we're initializing the structure by copying the tunnel info together with the options, and this triggers a warning for a potential memcpy overflow, since the compiler estimates that the options can't fit into the structure, even though the memory for them is actually allocated. memcpy: detected buffer overflow: 104 byte write of buffer size 96 WARNING: CPU: X PID: Y at lib/string_helpers.c:1036 __fortify_report skb_tunnel_info_unclone+0x179/0x190 geneve_xmit+0x7fe/0xe00 The issue is triggered when built with clang and source fortification. Fix that by doing the copy in two stages: first - the main data with the options_len, then the options. This way the correct length should be known at the time o...
5.5 Medium
CVSS3