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Re: [Qemu-devel] [PATVH v2] net: ne2000: fix bounds check in ioport oper
From: |
Jason Wang |
Subject: |
Re: [Qemu-devel] [PATVH v2] net: ne2000: fix bounds check in ioport operations |
Date: |
Thu, 31 Dec 2015 13:20:10 +0800 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 |
On 12/31/2015 12:53 PM, P J P wrote:
> From: Prasad J Pandit <address@hidden>
>
> While doing ioport r/w operations, ne2000 device emulation suffers
> from OOB r/w errors. Update respective array bounds check to avoid
> OOB access.
>
> Reported-by: Ling Liu <address@hidden>
> Signed-off-by: Prasad J Pandit <address@hidden>
> ---
> hw/net/ne2000.c | 28 +++++++++++++++-------------
> 1 file changed, 15 insertions(+), 13 deletions(-)
>
> Updated as per review in
> -> https://lists.gnu.org/archive/html/qemu-devel/2015-12/msg04856.html
>
> diff --git a/hw/net/ne2000.c b/hw/net/ne2000.c
> index 010f9ef..d1f764b 100644
> --- a/hw/net/ne2000.c
> +++ b/hw/net/ne2000.c
> @@ -447,8 +447,7 @@ static uint32_t ne2000_ioport_read(void *opaque, uint32_t
> addr)
> static inline void ne2000_mem_writeb(NE2000State *s, uint32_t addr,
> uint32_t val)
> {
> - if (addr < 32 ||
> - (addr >= NE2000_PMEM_START && addr < NE2000_MEM_SIZE)) {
> + if (addr < 32 || (addr >= NE2000_PMEM_START && addr < NE2000_MEM_SIZE)) {
The change is unnecessary.
> s->mem[addr] = val;
> }
> }
> @@ -457,9 +456,10 @@ static inline void ne2000_mem_writew(NE2000State *s,
> uint32_t addr,
> uint32_t val)
> {
> addr &= ~1; /* XXX: check exact behaviour if not even */
> - if (addr < 32 ||
> - (addr >= NE2000_PMEM_START && addr < NE2000_MEM_SIZE)) {
> - *(uint16_t *)(s->mem + addr) = cpu_to_le16(val);
> + if (addr < 32
> + || (addr >= NE2000_PMEM_START
> + && addr + sizeof(uint16_t) < NE2000_MEM_SIZE)) {
I think you mean '<=' instead of '<' here? (And for the other checks below).
> + *(uint16_t *)(s->mem + addr) = cpu_to_le16(data);
> }
> }
>
> @@ -467,16 +467,16 @@ static inline void ne2000_mem_writel(NE2000State *s,
> uint32_t addr,
> uint32_t val)
> {
> addr &= ~1; /* XXX: check exact behaviour if not even */
> - if (addr < 32 ||
> - (addr >= NE2000_PMEM_START && addr < NE2000_MEM_SIZE)) {
> + if (addr < 32
> + || (addr >= NE2000_PMEM_START
> + && addr + sizeof(uint32_t) < NE2000_MEM_SIZE)) {
> stl_le_p(s->mem + addr, val);
> }
> }
>
> static inline uint32_t ne2000_mem_readb(NE2000State *s, uint32_t addr)
> {
> - if (addr < 32 ||
> - (addr >= NE2000_PMEM_START && addr < NE2000_MEM_SIZE)) {
> + if (addr < 32 || (addr >= NE2000_PMEM_START && addr < NE2000_MEM_SIZE)) {
> return s->mem[addr];
> } else {
> return 0xff;
> @@ -486,8 +486,9 @@ static inline uint32_t ne2000_mem_readb(NE2000State *s,
> uint32_t addr)
> static inline uint32_t ne2000_mem_readw(NE2000State *s, uint32_t addr)
> {
> addr &= ~1; /* XXX: check exact behaviour if not even */
> - if (addr < 32 ||
> - (addr >= NE2000_PMEM_START && addr < NE2000_MEM_SIZE)) {
> + if (addr < 32
> + || (addr >= NE2000_PMEM_START
> + && addr + sizeof(uint16_t) < NE2000_MEM_SIZE)) {
> return le16_to_cpu(*(uint16_t *)(s->mem + addr));
> } else {
> return 0xffff;
> @@ -497,8 +498,9 @@ static inline uint32_t ne2000_mem_readw(NE2000State *s,
> uint32_t addr)
> static inline uint32_t ne2000_mem_readl(NE2000State *s, uint32_t addr)
> {
> addr &= ~1; /* XXX: check exact behaviour if not even */
> - if (addr < 32 ||
> - (addr >= NE2000_PMEM_START && addr < NE2000_MEM_SIZE)) {
> + if (addr < 32
> + || (addr >= NE2000_PMEM_START
> + && addr + sizeof(uint32_t) < NE2000_MEM_SIZE)) {
> return ldl_le_p(s->mem + addr);
> } else {
> return 0xffffffff;