Описание
In the Linux kernel, the following vulnerability has been resolved:
net: deal with integer overflows in kmalloc_reserve()
Blamed commit changed: ptr = kmalloc(size); if (ptr) size = ksize(ptr);
This allowed various crash as reported by syzbot [1] and Kyle Zeng.
Problem is that if @size is bigger than 0x80000001, kmalloc_size_roundup(size) returns 2^32.
kmalloc_reserve() uses a 32bit variable (obj_size), so 2^32 is truncated to 0.
kmalloc(0) returns ZERO_SIZE_PTR which is not handled by skb allocations.
Following trace can be triggered if a netdev->mtu is set close to 0x7fffffff
We might in the future limit netdev->mtu to more sensible limit (like KMALLOC_MAX_SIZE).
This patch is based on a syzbot report, and also a report and tentative fix from Kyle Zeng.
[1] BUG: KASAN: user-memory-access in __build_skb_around net/core/skbuff.c:294 [inline] BUG: KASAN: user-memory-access in __alloc_skb+0x3c4/0x6e8
EPSS
Дефекты
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: net: deal with integer overflows in kmalloc_reserve() Blamed commit changed: ptr = kmalloc(size); if (ptr) size = ksize(ptr); size = kmalloc_size_roundup(size); ptr = kmalloc(size); This allowed various crash as reported by syzbot [1] and Kyle Zeng. Problem is that if @size is bigger than 0x80000001, kmalloc_size_roundup(size) returns 2^32. kmalloc_reserve() uses a 32bit variable (obj_size), so 2^32 is truncated to 0. kmalloc(0) returns ZERO_SIZE_PTR which is not handled by skb allocations. Following trace can be triggered if a netdev->mtu is set close to 0x7fffffff We might in the future limit netdev->mtu to more sensible limit (like KMALLOC_MAX_SIZE). This patch is based on a syzbot report, and also a report and tentative fix from Kyle Zeng. [1] BUG: KASAN: user-memory-access in __build_skb_around net/core/skbuff.c:294 [inline] BUG: KASAN: user-memory-access in __alloc_skb+0x3c4/0x6e8 net/core/skbuff.c:527 Write o...
In the Linux kernel, the following vulnerability has been resolved: n ...
In the Linux kernel, the following vulnerability has been resolved: net: deal with integer overflows in kmalloc_reserve() Blamed commit changed: ptr = kmalloc(size); if (ptr) size = ksize(ptr); size = kmalloc_size_roundup(size); ptr = kmalloc(size); This allowed various crash as reported by syzbot [1] and Kyle Zeng. Problem is that if @size is bigger than 0x80000001, kmalloc_size_roundup(size) returns 2^32. kmalloc_reserve() uses a 32bit variable (obj_size), so 2^32 is truncated to 0. kmalloc(0) returns ZERO_SIZE_PTR which is not handled by skb allocations. Following trace can be triggered if a netdev->mtu is set close to 0x7fffffff We might in the future limit netdev->mtu to more sensible limit (like KMALLOC_MAX_SIZE). This patch is based on a syzbot report, and also a report and tentative fix from Kyle Zeng. [1] BUG: KASAN: user-memory-access in __build_skb_around net/core/skbuff.c:294 [inline] BUG: KASAN: user-memory-access in __alloc_skb+0x3c4/0x...
EPSS