linux-stable.git/include, branch v4.19.321

net: busy-poll: use ktime_get_ns() instead of local_clock()

2024-09-04T11:13:08+00:00

[ Upstream commit 0870b0d8b393dde53106678a1e2cec9dfa52f9b7 ]

Typically, busy-polling durations are below 100 usec.

When/if the busy-poller thread migrates to another cpu,
local_clock() can be off by +/-2msec or more for small
values of HZ, depending on the platform.

Use ktimer_get_ns() to ensure deterministic behavior,
which is the whole point of busy-polling.

Fixes: 060212928670 ("net: add low latency socket poll")
Fixes: 9a3c71aa8024 ("net: convert low latency sockets to sched_clock()")
Fixes: 37089834528b ("sched, net: Fixup busy_loop_us_clock()")
Signed-off-by: Eric Dumazet 
Cc: Mina Almasry 
Cc: Willem de Bruijn 
Reviewed-by: Joe Damato 
Link: https://patch.msgid.link/20240827114916.223377-1-edumazet@google.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

fbcon: Prevent that screen size is smaller than font size

2024-09-04T11:13:08+00:00

commit e64242caef18b4a5840b0e7a9bff37abd4f4f933 upstream.

We need to prevent that users configure a screen size which is smaller than the
currently selected font size. Otherwise rendering chars on the screen will
access memory outside the graphics memory region.

This patch adds a new function fbcon_modechange_possible() which
implements this check and which later may be extended with other checks
if necessary.  The new function is called from the FBIOPUT_VSCREENINFO
ioctl handler in fbmem.c, which will return -EINVAL if userspace asked
for a too small screen size.

Signed-off-by: Helge Deller 
Reviewed-by: Geert Uytterhoeven 
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Hugo SIMELIERE 
Signed-off-by: Greg Kroah-Hartman

kcm: Serialise kcm_sendmsg() for the same socket.

2024-09-04T11:13:05+00:00

[ Upstream commit 807067bf014d4a3ae2cc55bd3de16f22a01eb580 ]

syzkaller reported UAF in kcm_release(). [0]

The scenario is

  1. Thread A builds a skb with MSG_MORE and sets kcm->seq_skb.

  2. Thread A resumes building skb from kcm->seq_skb but is blocked
     by sk_stream_wait_memory()

  3. Thread B calls sendmsg() concurrently, finishes building kcm->seq_skb
     and puts the skb to the write queue

  4. Thread A faces an error and finally frees skb that is already in the
     write queue

  5. kcm_release() does double-free the skb in the write queue

When a thread is building a MSG_MORE skb, another thread must not touch it.

Let's add a per-sk mutex and serialise kcm_sendmsg().

[0]:
BUG: KASAN: slab-use-after-free in __skb_unlink include/linux/skbuff.h:2366 [inline]
BUG: KASAN: slab-use-after-free in __skb_dequeue include/linux/skbuff.h:2385 [inline]
BUG: KASAN: slab-use-after-free in __skb_queue_purge_reason include/linux/skbuff.h:3175 [inline]
BUG: KASAN: slab-use-after-free in __skb_queue_purge include/linux/skbuff.h:3181 [inline]
BUG: KASAN: slab-use-after-free in kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691
Read of size 8 at addr ffff0000ced0fc80 by task syz-executor329/6167

CPU: 1 PID: 6167 Comm: syz-executor329 Tainted: G    B              6.8.0-rc5-syzkaller-g9abbc24128bc #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call trace:
 dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:291
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:298
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x178/0x518 mm/kasan/report.c:488
 kasan_report+0xd8/0x138 mm/kasan/report.c:601
 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381
 __skb_unlink include/linux/skbuff.h:2366 [inline]
 __skb_dequeue include/linux/skbuff.h:2385 [inline]
 __skb_queue_purge_reason include/linux/skbuff.h:3175 [inline]
 __skb_queue_purge include/linux/skbuff.h:3181 [inline]
 kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691
 __sock_release net/socket.c:659 [inline]
 sock_close+0xa4/0x1e8 net/socket.c:1421
 __fput+0x30c/0x738 fs/file_table.c:376
 ____fput+0x20/0x30 fs/file_table.c:404
 task_work_run+0x230/0x2e0 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0x618/0x1f64 kernel/exit.c:871
 do_group_exit+0x194/0x22c kernel/exit.c:1020
 get_signal+0x1500/0x15ec kernel/signal.c:2893
 do_signal+0x23c/0x3b44 arch/arm64/kernel/signal.c:1249
 do_notify_resume+0x74/0x1f4 arch/arm64/kernel/entry-common.c:148
 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline]
 el0_svc+0xac/0x168 arch/arm64/kernel/entry-common.c:713
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598

Allocated by task 6166:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x40/0x78 mm/kasan/common.c:68
 kasan_save_alloc_info+0x70/0x84 mm/kasan/generic.c:626
 unpoison_slab_object mm/kasan/common.c:314 [inline]
 __kasan_slab_alloc+0x74/0x8c mm/kasan/common.c:340
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3813 [inline]
 slab_alloc_node mm/slub.c:3860 [inline]
 kmem_cache_alloc_node+0x204/0x4c0 mm/slub.c:3903
 __alloc_skb+0x19c/0x3d8 net/core/skbuff.c:641
 alloc_skb include/linux/skbuff.h:1296 [inline]
 kcm_sendmsg+0x1d3c/0x2124 net/kcm/kcmsock.c:783
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 sock_sendmsg+0x220/0x2c0 net/socket.c:768
 splice_to_socket+0x7cc/0xd58 fs/splice.c:889
 do_splice_from fs/splice.c:941 [inline]
 direct_splice_actor+0xec/0x1d8 fs/splice.c:1164
 splice_direct_to_actor+0x438/0xa0c fs/splice.c:1108
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0x1e4/0x304 fs/splice.c:1233
 do_sendfile+0x460/0xb3c fs/read_write.c:1295
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64 fs/read_write.c:1348 [inline]
 __arm64_sys_sendfile64+0x160/0x3b4 fs/read_write.c:1348
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598

Freed by task 6167:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x40/0x78 mm/kasan/common.c:68
 kasan_save_free_info+0x5c/0x74 mm/kasan/generic.c:640
 poison_slab_object+0x124/0x18c mm/kasan/common.c:241
 __kasan_slab_free+0x3c/0x78 mm/kasan/common.c:257
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2121 [inline]
 slab_free mm/slub.c:4299 [inline]
 kmem_cache_free+0x15c/0x3d4 mm/slub.c:4363
 kfree_skbmem+0x10c/0x19c
 __kfree_skb net/core/skbuff.c:1109 [inline]
 kfree_skb_reason+0x240/0x6f4 net/core/skbuff.c:1144
 kfree_skb include/linux/skbuff.h:1244 [inline]
 kcm_release+0x104/0x4c8 net/kcm/kcmsock.c:1685
 __sock_release net/socket.c:659 [inline]
 sock_close+0xa4/0x1e8 net/socket.c:1421
 __fput+0x30c/0x738 fs/file_table.c:376
 ____fput+0x20/0x30 fs/file_table.c:404
 task_work_run+0x230/0x2e0 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0x618/0x1f64 kernel/exit.c:871
 do_group_exit+0x194/0x22c kernel/exit.c:1020
 get_signal+0x1500/0x15ec kernel/signal.c:2893
 do_signal+0x23c/0x3b44 arch/arm64/kernel/signal.c:1249
 do_notify_resume+0x74/0x1f4 arch/arm64/kernel/entry-common.c:148
 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline]
 el0_svc+0xac/0x168 arch/arm64/kernel/entry-common.c:713
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598

The buggy address belongs to the object at ffff0000ced0fc80
 which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 0 bytes inside of
 freed 240-byte region [ffff0000ced0fc80, ffff0000ced0fd70)

The buggy address belongs to the physical page:
page:00000000d35f4ae4 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10ed0f
flags: 0x5ffc00000000800(slab|node=0|zone=2|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 05ffc00000000800 ffff0000c1cbf640 fffffdffc3423100 dead000000000004
raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000ced0fb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000ced0fc00: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
>ffff0000ced0fc80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff0000ced0fd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
 ffff0000ced0fd80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb

Fixes: ab7ac4eb9832 ("kcm: Kernel Connection Multiplexor module")
Reported-by: syzbot+b72d86aa5df17ce74c60@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=b72d86aa5df17ce74c60
Tested-by: syzbot+b72d86aa5df17ce74c60@syzkaller.appspotmail.com
Signed-off-by: Kuniyuki Iwashima 
Reviewed-by: Eric Dumazet 
Link: https://patch.msgid.link/20240815220437.69511-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

block: use "unsigned long" for blk_validate_block_size().

2024-09-04T11:13:04+00:00

commit 37ae5a0f5287a52cf51242e76ccf198d02ffe495 upstream.

Since lo_simple_ioctl(LOOP_SET_BLOCK_SIZE) and ioctl(NBD_SET_BLKSIZE) pass
user-controlled "unsigned long arg" to blk_validate_block_size(),
"unsigned long" should be used for validation.

Signed-off-by: Tetsuo Handa 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/9ecbf057-4375-c2db-ab53-e4cc0dff953d@i-love.sakura.ne.jp
Signed-off-by: Jens Axboe 
Signed-off-by: David Hunter 
Signed-off-by: Greg Kroah-Hartman

overflow: Implement size_t saturating arithmetic helpers

2024-09-04T11:13:00+00:00

commit e1be43d9b5d0d1310dbd90185a8e5c7145dde40f upstream.

In order to perform more open-coded replacements of common allocation
size arithmetic, the kernel needs saturating (SIZE_MAX) helpers for
multiplication, addition, and subtraction. For example, it is common in
allocators, especially on realloc, to add to an existing size:

    p = krealloc(map->patch,
                 sizeof(struct reg_sequence) * (map->patch_regs + num_regs),
                 GFP_KERNEL);

There is no existing saturating replacement for this calculation, and
just leaving the addition open coded inside array_size() could
potentially overflow as well. For example, an overflow in an expression
for a size_t argument might wrap to zero:

    array_size(anything, something_at_size_max + 1) == 0

Introduce size_mul(), size_add(), and size_sub() helpers that
implicitly promote arguments to size_t and saturated calculations for
use in allocations. With these helpers it is also possible to redefine
array_size(), array3_size(), flex_array_size(), and struct_size() in
terms of the new helpers.

As with the check_*_overflow() helpers, the new helpers use __must_check,
though what is really desired is a way to make sure that assignment is
only to a size_t lvalue. Without this, it's still possible to introduce
overflow/underflow via type conversion (i.e. from size_t to int).
Enforcing this will currently need to be left to static analysis or
future use of -Wconversion.

Additionally update the overflow unit tests to force runtime evaluation
for the pathological cases.

Cc: Rasmus Villemoes 
Cc: Gustavo A. R. Silva 
Cc: Nathan Chancellor 
Cc: Jason Gunthorpe 
Cc: Nick Desaulniers 
Cc: Leon Romanovsky 
Cc: Keith Busch 
Cc: Len Baker 
Signed-off-by: Kees Cook 
Signed-off-by: Greg Kroah-Hartman

overflow.h: Add flex_array_size() helper

2024-09-04T11:12:59+00:00

commit b19d57d0f3cc6f1022edf94daf1d70506a09e3c2 upstream.

Add flex_array_size() helper for the calculation of the size, in bytes,
of a flexible array member contained within an enclosing structure.

Example of usage:

struct something {
	size_t count;
	struct foo items[];
};

struct something *instance;

instance = kmalloc(struct_size(instance, items, count), GFP_KERNEL);
instance->count = count;
memcpy(instance->items, src, flex_array_size(instance, items, instance->count));

The helper returns SIZE_MAX on overflow instead of wrapping around.

Additionally replaces parameter "n" with "count" in struct_size() helper
for greater clarity and unification.

Signed-off-by: Gustavo A. R. Silva 
Link: https://lore.kernel.org/r/20200609012233.GA3371@embeddedor
Signed-off-by: Kees Cook 
Signed-off-by: Greg Kroah-Hartman

fix bitmap corruption on close_range() with CLOSE_RANGE_UNSHARE

2024-09-04T11:12:59+00:00

commit 9a2fa1472083580b6c66bdaf291f591e1170123a upstream.

copy_fd_bitmaps(new, old, count) is expected to copy the first
count/BITS_PER_LONG bits from old->full_fds_bits[] and fill
the rest with zeroes.  What it does is copying enough words
(BITS_TO_LONGS(count/BITS_PER_LONG)), then memsets the rest.
That works fine, *if* all bits past the cutoff point are
clear.  Otherwise we are risking garbage from the last word
we'd copied.

For most of the callers that is true - expand_fdtable() has
count equal to old->max_fds, so there's no open descriptors
past count, let alone fully occupied words in ->open_fds[],
which is what bits in ->full_fds_bits[] correspond to.

The other caller (dup_fd()) passes sane_fdtable_size(old_fdt, max_fds),
which is the smallest multiple of BITS_PER_LONG that covers all
opened descriptors below max_fds.  In the common case (copying on
fork()) max_fds is ~0U, so all opened descriptors will be below
it and we are fine, by the same reasons why the call in expand_fdtable()
is safe.

Unfortunately, there is a case where max_fds is less than that
and where we might, indeed, end up with junk in ->full_fds_bits[] -
close_range(from, to, CLOSE_RANGE_UNSHARE) with
	* descriptor table being currently shared
	* 'to' being above the current capacity of descriptor table
	* 'from' being just under some chunk of opened descriptors.
In that case we end up with observably wrong behaviour - e.g. spawn
a child with CLONE_FILES, get all descriptors in range 0..127 open,
then close_range(64, ~0U, CLOSE_RANGE_UNSHARE) and watch dup(0) ending
up with descriptor #128, despite #64 being observably not open.

The minimally invasive fix would be to deal with that in dup_fd().
If this proves to add measurable overhead, we can go that way, but
let's try to fix copy_fd_bitmaps() first.

* new helper: bitmap_copy_and_expand(to, from, bits_to_copy, size).
* make copy_fd_bitmaps() take the bitmap size in words, rather than
bits; it's 'count' argument is always a multiple of BITS_PER_LONG,
so we are not losing any information, and that way we can use the
same helper for all three bitmaps - compiler will see that count
is a multiple of BITS_PER_LONG for the large ones, so it'll generate
plain memcpy()+memset().

Reproducer added to tools/testing/selftests/core/close_range_test.c

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman

bitmap: introduce generic optimized bitmap_size()

2024-09-04T11:12:59+00:00

commit a37fbe666c016fd89e4460d0ebfcea05baba46dc upstream.

The number of times yet another open coded
`BITS_TO_LONGS(nbits) * sizeof(long)` can be spotted is huge.
Some generic helper is long overdue.

Add one, bitmap_size(), but with one detail.
BITS_TO_LONGS() uses DIV_ROUND_UP(). The latter works well when both
divident and divisor are compile-time constants or when the divisor
is not a pow-of-2. When it is however, the compilers sometimes tend
to generate suboptimal code (GCC 13):

48 83 c0 3f          	add    $0x3f,%rax
48 c1 e8 06          	shr    $0x6,%rax
48 8d 14 c5 00 00 00 00	lea    0x0(,%rax,8),%rdx

%BITS_PER_LONG is always a pow-2 (either 32 or 64), but GCC still does
full division of `nbits + 63` by it and then multiplication by 8.
Instead of BITS_TO_LONGS(), use ALIGN() and then divide by 8. GCC:

8d 50 3f             	lea    0x3f(%rax),%edx
c1 ea 03             	shr    $0x3,%edx
81 e2 f8 ff ff 1f    	and    $0x1ffffff8,%edx

Now it shifts `nbits + 63` by 3 positions (IOW performs fast division
by 8) and then masks bits[2:0]. bloat-o-meter:

add/remove: 0/0 grow/shrink: 20/133 up/down: 156/-773 (-617)

Clang does it better and generates the same code before/after starting
from -O1, except that with the ALIGN() approach it uses %edx and thus
still saves some bytes:

add/remove: 0/0 grow/shrink: 9/133 up/down: 18/-538 (-520)

Note that we can't expand DIV_ROUND_UP() by adding a check and using
this approach there, as it's used in array declarations where
expressions are not allowed.
Add this helper to tools/ as well.

Reviewed-by: Przemek Kitszel 
Acked-by: Yury Norov 
Signed-off-by: Alexander Lobakin 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_tables: use timestamp to check for set element timeout

2024-08-19T03:32:17+00:00

commit 7395dfacfff65e9938ac0889dafa1ab01e987d15 upstream

Add a timestamp field at the beginning of the transaction, store it
in the nftables per-netns area.

Update set backend .insert, .deactivate and sync gc path to use the
timestamp, this avoids that an element expires while control plane
transaction is still unfinished.

.lookup and .update, which are used from packet path, still use the
current time to check if the element has expired. And .get path and dump
also since this runs lockless under rcu read size lock. Then, there is
async gc which also needs to check the current time since it runs
asynchronously from a workqueue.

[ NB: rbtree GC updates has been excluded because GC is asynchronous. ]

Fixes: c3e1b005ed1c ("netfilter: nf_tables: add set element timeout support")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

bpf: kprobe: remove unused declaring of bpf_kprobe_override

2024-08-19T03:32:14+00:00

[ Upstream commit 0e8b53979ac86eddb3fd76264025a70071a25574 ]

After the commit 66665ad2f102 ("tracing/kprobe: bpf: Compare instruction
pointer with original one"), "bpf_kprobe_override" is not used anywhere
anymore, and we can remove it now.

Link: https://lore.kernel.org/all/20240710085939.11520-1-dongml2@chinatelecom.cn/

Fixes: 66665ad2f102 ("tracing/kprobe: bpf: Compare instruction pointer with original one")
Signed-off-by: Menglong Dong 
Acked-by: Jiri Olsa 
Signed-off-by: Masami Hiramatsu (Google) 
Signed-off-by: Sasha Levin