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[components][lwp] harden sys_getaddrinfo user pointer handling #11977

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Merged
Rbb666 merged 1 commit into from
Nov 3, 2026
Merged

[components][lwp] harden sys_getaddrinfo user pointer handling #11977

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74 changes: 57 additions & 17 deletions components/lwp/syscall/syscall_netdb.c
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Original file line number Diff line number Diff line change
Expand Up @@ -63,16 +63,24 @@ sysret_t sys_getaddrinfo(const char *nodename,
char *k_nodename = NULL;
char *k_servname = NULL;
struct addrinfo *k_hints = NULL;
struct musl_addrinfo k_res_musl = { 0 };
struct musl_addrinfo k_hints_musl = { 0 };
#ifdef ARCH_MM_MMU
int len = 0;
#endif

/*
* Work on a kernel copy of res: ai_addr is a user pointer and must not be
* re-read from user memory after validation (TOCTOU).
*/
#ifdef ARCH_MM_MMU
if (!lwp_user_accessable((void *)res, sizeof(*res)))
if (lwp_get_from_user(&k_res_musl, (void *)res, sizeof(k_res_musl)) != sizeof(k_res_musl))
{
SET_ERRNO(EFAULT);
goto exit;
}
#else
k_res_musl = *res;
#endif
if (nodename)
{
Expand Down Expand Up @@ -122,7 +130,7 @@ sysret_t sys_getaddrinfo(const char *nodename,
goto exit;
}

if (lwp_get_from_user(k_servname, (void *)servname, len + 1) < 0)
if (lwp_get_from_user(k_servname, (void *)servname, len + 1) != len + 1)
{
SET_ERRNO(EFAULT);
goto exit;
Expand All @@ -140,45 +148,73 @@ sysret_t sys_getaddrinfo(const char *nodename,
if (hints)
{
#ifdef ARCH_MM_MMU
if (!lwp_user_accessable((void *)hints, sizeof(*hints)))
if (lwp_get_from_user(&k_hints_musl, (void *)hints, sizeof(k_hints_musl)) != sizeof(k_hints_musl))
{
SET_ERRNO(EFAULT);
goto exit;
}
#else
k_hints_musl = *hints;
#endif
k_hints = (struct addrinfo *)rt_malloc(sizeof *hints);
k_hints = (struct addrinfo *)rt_malloc(sizeof(*k_hints));
if (!k_hints)
{
SET_ERRNO(ENOMEM);
goto exit;
}

rt_memset(k_hints, 0x0, sizeof(struct addrinfo));
k_hints->ai_flags = hints->ai_flags;
k_hints->ai_family = hints->ai_family;
k_hints->ai_socktype = hints->ai_socktype;
k_hints->ai_protocol = hints->ai_protocol;
k_hints->ai_addrlen = hints->ai_addrlen;
rt_memset(k_hints, 0x0, sizeof(*k_hints));
k_hints->ai_flags = k_hints_musl.ai_flags;
k_hints->ai_family = k_hints_musl.ai_family;
k_hints->ai_socktype = k_hints_musl.ai_socktype;
k_hints->ai_protocol = k_hints_musl.ai_protocol;
k_hints->ai_addrlen = k_hints_musl.ai_addrlen;
}

ret = sal_getaddrinfo(k_nodename, k_servname, k_hints, &k_res);
if (ret == 0)
{
/* set sockaddr */
sockaddr_tomusl(k_res->ai_addr, res->ai_addr);
res->ai_addrlen = k_res->ai_addrlen;
if (k_res->ai_addr && k_res_musl.ai_addr)
{
#ifdef ARCH_MM_MMU
struct musl_sockaddr k_sockaddr;

sockaddr_tomusl(k_res->ai_addr, &k_sockaddr);
if (lwp_put_to_user(k_res_musl.ai_addr, &k_sockaddr, sizeof(k_sockaddr)) != sizeof(k_sockaddr))
{
SET_ERRNO(EFAULT);
ret = -1;
goto exit;
}
#else
sockaddr_tomusl(k_res->ai_addr, k_res_musl.ai_addr);
#endif
}
k_res_musl.ai_addrlen = k_res->ai_addrlen;

/* set up addrinfo */
res->ai_family = k_res->ai_family;
res->ai_flags = k_res->ai_flags;
res->ai_next = NULL;
k_res_musl.ai_family = k_res->ai_family;
k_res_musl.ai_flags = k_res->ai_flags;
k_res_musl.ai_next = NULL;

if (hints != NULL)
{
/* copy socktype & protocol from hints if specified */
res->ai_socktype = hints->ai_socktype;
res->ai_protocol = hints->ai_protocol;
k_res_musl.ai_socktype = k_hints_musl.ai_socktype;
k_res_musl.ai_protocol = k_hints_musl.ai_protocol;
}

#ifdef ARCH_MM_MMU
if (lwp_put_to_user(res, &k_res_musl, sizeof(k_res_musl)) != sizeof(k_res_musl))
{
SET_ERRNO(EFAULT);
ret = -1;
goto exit;
}
#else
*res = k_res_musl;
#endif

sal_freeaddrinfo(k_res);
k_res = NULL;
Expand Down Expand Up @@ -215,6 +251,10 @@ sysret_t sys_getaddrinfo(const char *nodename,
{
rt_free(k_hints);
}
if (k_res)
{
sal_freeaddrinfo(k_res);
}

return ret;
}
Expand Down
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