https://github.com/torvalds/linux
Revision c6ec179a0082e2e76e3a72050c2b99d3d0f3da3f authored by Ganesh Goudar on 19 December 2018, 11:48:22 UTC, committed by David S. Miller on 20 December 2018, 00:28:50 UTC
create_ctx can be called from atomic context, hence use GFP_ATOMIC instead of GFP_KERNEL. [ 395.962599] BUG: sleeping function called from invalid context at mm/slab.h:421 [ 395.979896] in_atomic(): 1, irqs_disabled(): 0, pid: 16254, name: openssl [ 395.996564] 2 locks held by openssl/16254: [ 396.010492] #0: 00000000347acb52 (sk_lock-AF_INET){+.+.}, at: do_tcp_setsockopt.isra.44+0x13b/0x9a0 [ 396.029838] #1: 000000006c9552b5 (device_spinlock){+...}, at: tls_init+0x1d/0x280 [ 396.047675] CPU: 5 PID: 16254 Comm: openssl Tainted: G O 4.20.0-rc6+ #25 [ 396.066019] Hardware name: Supermicro X10SRA-F/X10SRA-F, BIOS 2.0c 09/25/2017 [ 396.083537] Call Trace: [ 396.096265] dump_stack+0x5e/0x8b [ 396.109876] ___might_sleep+0x216/0x250 [ 396.123940] kmem_cache_alloc_trace+0x1b0/0x240 [ 396.138800] create_ctx+0x1f/0x60 [ 396.152504] tls_init+0xbd/0x280 [ 396.166135] tcp_set_ulp+0x191/0x2d0 [ 396.180035] ? tcp_set_ulp+0x2c/0x2d0 [ 396.193960] do_tcp_setsockopt.isra.44+0x148/0x9a0 [ 396.209013] __sys_setsockopt+0x7c/0xe0 [ 396.223054] __x64_sys_setsockopt+0x20/0x30 [ 396.237378] do_syscall_64+0x4a/0x180 [ 396.251200] entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: df9d4a178022 ("net/tls: sleeping function from invalid context") Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 1875a9a
Tip revision: c6ec179a0082e2e76e3a72050c2b99d3d0f3da3f authored by Ganesh Goudar on 19 December 2018, 11:48:22 UTC
net/tls: allocate tls context using GFP_ATOMIC
net/tls: allocate tls context using GFP_ATOMIC
Tip revision: c6ec179
strnlen_user.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/uaccess.h>
#include <asm/word-at-a-time.h>
/* Set bits in the first 'n' bytes when loaded from memory */
#ifdef __LITTLE_ENDIAN
# define aligned_byte_mask(n) ((1ul << 8*(n))-1)
#else
# define aligned_byte_mask(n) (~0xfful << (BITS_PER_LONG - 8 - 8*(n)))
#endif
/*
* Do a strnlen, return length of string *with* final '\0'.
* 'count' is the user-supplied count, while 'max' is the
* address space maximum.
*
* Return 0 for exceptions (which includes hitting the address
* space maximum), or 'count+1' if hitting the user-supplied
* maximum count.
*
* NOTE! We can sometimes overshoot the user-supplied maximum
* if it fits in a aligned 'long'. The caller needs to check
* the return value against "> max".
*/
static inline long do_strnlen_user(const char __user *src, unsigned long count, unsigned long max)
{
const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS;
long align, res = 0;
unsigned long c;
/*
* Truncate 'max' to the user-specified limit, so that
* we only have one limit we need to check in the loop
*/
if (max > count)
max = count;
/*
* Do everything aligned. But that means that we
* need to also expand the maximum..
*/
align = (sizeof(long) - 1) & (unsigned long)src;
src -= align;
max += align;
unsafe_get_user(c, (unsigned long __user *)src, efault);
c |= aligned_byte_mask(align);
for (;;) {
unsigned long data;
if (has_zero(c, &data, &constants)) {
data = prep_zero_mask(c, data, &constants);
data = create_zero_mask(data);
return res + find_zero(data) + 1 - align;
}
res += sizeof(unsigned long);
/* We already handled 'unsigned long' bytes. Did we do it all ? */
if (unlikely(max <= sizeof(unsigned long)))
break;
max -= sizeof(unsigned long);
unsafe_get_user(c, (unsigned long __user *)(src+res), efault);
}
res -= align;
/*
* Uhhuh. We hit 'max'. But was that the user-specified maximum
* too? If so, return the marker for "too long".
*/
if (res >= count)
return count+1;
/*
* Nope: we hit the address space limit, and we still had more
* characters the caller would have wanted. That's 0.
*/
efault:
return 0;
}
/**
* strnlen_user: - Get the size of a user string INCLUDING final NUL.
* @str: The string to measure.
* @count: Maximum count (including NUL character)
*
* Context: User context only. This function may sleep if pagefaults are
* enabled.
*
* Get the size of a NUL-terminated string in user space.
*
* Returns the size of the string INCLUDING the terminating NUL.
* If the string is too long, returns a number larger than @count. User
* has to check the return value against "> count".
* On exception (or invalid count), returns 0.
*
* NOTE! You should basically never use this function. There is
* almost never any valid case for using the length of a user space
* string, since the string can be changed at any time by other
* threads. Use "strncpy_from_user()" instead to get a stable copy
* of the string.
*/
long strnlen_user(const char __user *str, long count)
{
unsigned long max_addr, src_addr;
if (unlikely(count <= 0))
return 0;
max_addr = user_addr_max();
src_addr = (unsigned long)str;
if (likely(src_addr < max_addr)) {
unsigned long max = max_addr - src_addr;
long retval;
user_access_begin();
retval = do_strnlen_user(str, count, max);
user_access_end();
return retval;
}
return 0;
}
EXPORT_SYMBOL(strnlen_user);
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