commit d839a656d0f3caca9f96e9bf912fd394ac6a11bc upstream.
It seems that the pointer-to-kretprobe "rp" within the kretprobe_holder is
RCU-managed, based on the (non-rethook) implementation of get_kretprobe().
The thought behind this patch is to make use of the RCU API where possible
when accessing this pointer so that the needed barriers are always in place
and to self-document the code.
The __rcu annotation to "rp" allows for sparse RCU checking. Plain writes
done to the "rp" pointer are changed to make use of the RCU macro for
assignment. For the single read, the implementation of get_kretprobe()
is simplified by making use of an RCU macro which accomplishes the same,
but note that the log warning text will be more generic.
I did find that there is a difference in assembly generated between the
usage of the RCU macros vs without. For example, on arm64, when using
rcu_assign_pointer(), the corresponding store instruction is a
store-release (STLR) which has an implicit barrier. When normal assignment
is done, a regular store (STR) is found. In the macro case, this seems to
be a result of rcu_assign_pointer() using smp_store_release() when the
value to write is not NULL.
Link: https://lore.kernel.org/all/20231122132058.3359-1-inwardvessel@gmail.com/
Fixes: d741bf41d7c7 ("kprobes: Remove kretprobe hash")
Cc: stable@vger.kernel.org
Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e0f04e41e8eedd4e5a1275f2318df7e1841855f2 upstream.
Invoke drm_plane_helper_funcs.end_fb_access before
drm_atomic_helper_commit_hw_done(). The latter function hands over
ownership of the plane state to the following commit, which might
free it. Releasing resources in end_fb_access then operates on undefined
state. This bug has been observed with non-blocking commits when they
are being queued up quickly.
Here is an example stack trace from the bug report. The plane state has
been free'd already, so the pages for drm_gem_fb_vunmap() are gone.
Unable to handle kernel paging request at virtual address 0000000100000049
[...]
drm_gem_fb_vunmap+0x18/0x74
drm_gem_end_shadow_fb_access+0x1c/0x2c
drm_atomic_helper_cleanup_planes+0x58/0xd8
drm_atomic_helper_commit_tail+0x90/0xa0
commit_tail+0x15c/0x188
commit_work+0x14/0x20
Fix this by running end_fb_access immediately after updating all planes
in drm_atomic_helper_commit_planes(). The existing clean-up helper
drm_atomic_helper_cleanup_planes() now only handles cleanup_fb.
For aborted commits, roll back from drm_atomic_helper_prepare_planes()
in the new helper drm_atomic_helper_unprepare_planes(). This case is
different from regular cleanup, as we have to release the new state;
regular cleanup releases the old state. The new helper also invokes
cleanup_fb for all planes.
The changes mostly involve DRM's atomic helpers. Only two drivers, i915
and nouveau, implement their own commit function. Update them to invoke
drm_atomic_helper_unprepare_planes(). Drivers with custom commit_tail
function do not require changes.
v4:
* fix documentation (kernel test robot)
v3:
* add drm_atomic_helper_unprepare_planes() for rolling back
* use correct state for end_fb_access
v2:
* fix test in drm_atomic_helper_cleanup_planes()
Reported-by: Alyssa Ross <hi@alyssa.is>
Closes: https://lore.kernel.org/dri-devel/87leazm0ya.fsf@alyssa.is/
Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Fixes: 94d879eaf7fb ("drm/atomic-helper: Add {begin,end}_fb_access to plane helpers")
Tested-by: Alyssa Ross <hi@alyssa.is>
Reviewed-by: Alyssa Ross <hi@alyssa.is>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: <stable@vger.kernel.org> # v6.2+
Link: https://patchwork.freedesktop.org/patch/msgid/20231204083247.22006-1-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 187da0f8250aa94bd96266096aef6f694e0b4cd2 upstream.
The routine __vma_private_lock tests for the existence of a reserve map
associated with a private hugetlb mapping. A pointer to the reserve map
is in vma->vm_private_data. __vma_private_lock was checking the pointer
for NULL. However, it is possible that the low bits of the pointer could
be used as flags. In such instances, vm_private_data is not NULL and not
a valid pointer. This results in the null-ptr-deref reported by syzbot:
general protection fault, probably for non-canonical address 0xdffffc000000001d:
0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef]
CPU: 0 PID: 5048 Comm: syz-executor139 Not tainted 6.6.0-rc7-syzkaller-00142-g88
8cf78c29e2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 1
0/09/2023
RIP: 0010:__lock_acquire+0x109/0x5de0 kernel/locking/lockdep.c:5004
...
Call Trace:
<TASK>
lock_acquire kernel/locking/lockdep.c:5753 [inline]
lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5718
down_write+0x93/0x200 kernel/locking/rwsem.c:1573
hugetlb_vma_lock_write mm/hugetlb.c:300 [inline]
hugetlb_vma_lock_write+0xae/0x100 mm/hugetlb.c:291
__hugetlb_zap_begin+0x1e9/0x2b0 mm/hugetlb.c:5447
hugetlb_zap_begin include/linux/hugetlb.h:258 [inline]
unmap_vmas+0x2f4/0x470 mm/memory.c:1733
exit_mmap+0x1ad/0xa60 mm/mmap.c:3230
__mmput+0x12a/0x4d0 kernel/fork.c:1349
mmput+0x62/0x70 kernel/fork.c:1371
exit_mm kernel/exit.c:567 [inline]
do_exit+0x9ad/0x2a20 kernel/exit.c:861
__do_sys_exit kernel/exit.c:991 [inline]
__se_sys_exit kernel/exit.c:989 [inline]
__x64_sys_exit+0x42/0x50 kernel/exit.c:989
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Mask off low bit flags before checking for NULL pointer. In addition, the
reserve map only 'belongs' to the OWNER (parent in parent/child
relationships) so also check for the OWNER flag.
Link: https://lkml.kernel.org/r/20231114012033.259600-1-mike.kravetz@oracle.com
Reported-by: syzbot+6ada951e7c0f7bc8a71e@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-mm/00000000000078d1e00608d7878b@google.com/
Fixes: bf4916922c60 ("hugetlbfs: extend hugetlb_vma_lock to private VMAs")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Rik van Riel <riel@surriel.com>
Cc: Edward Adam Davis <eadavis@qq.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Tom Rix <trix@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 73424d00dc63ba681856e06cfb0a5abbdb62e2b5 upstream.
Clang static checker complains that value stored to 'from' is never read.
And memcpy_from_folio() only copy the last chunk memory from folio to
destination. Use 'to += chunk' to replace 'from += chunk' to fix this
typo problem.
Link: https://lkml.kernel.org/r/20231130034017.1210429-1-suhui@nfschina.com
Fixes: b23d03ef7af5 ("highmem: add memcpy_to_folio() and memcpy_from_folio()")
Signed-off-by: Su Hui <suhui@nfschina.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jiaqi Yan <jiaqiyan@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Tom Rix <trix@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a1461f1fd6cfdc4b8917c9d4a91e92605d1f28dc upstream.
Since the rethook::handler is an RCU-maganged pointer so that it will
notice readers the rethook is stopped (unregistered) or not, it should
be an __rcu pointer and use appropriate functions to be accessed. This
will use appropriate memory barrier when accessing it. OTOH,
rethook::data is never changed, so we don't need to check it in
get_kretprobe().
NOTE: To avoid sparse warning, rethook::handler is defined by a raw
function pointer type with __rcu instead of rethook_handler_t.
Link: https://lore.kernel.org/all/170126066201.398836.837498688669005979.stgit@devnote2/
Fixes: 54ecbe6f1ed5 ("rethook: Add a generic return hook")
Cc: stable@vger.kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202311241808.rv9ceuAh-lkp@intel.com/
Tested-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 4fbc3a52cd4d14de3793f4b2c721d7306ea84cf9 ]
64k pages introduce the situation in this diagram when the HCA 4k page
size is being used:
+-------------------------------------------+ <--- 64k aligned VA
| |
| HCA 4k page |
| |
+-------------------------------------------+
| o |
| |
| o |
| |
| o |
+-------------------------------------------+
| |
| HCA 4k page |
| |
+-------------------------------------------+ <--- Live HCA page
|OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO| <--- offset
| | <--- VA
| MR data |
+-------------------------------------------+
| |
| HCA 4k page |
| |
+-------------------------------------------+
| o |
| |
| o |
| |
| o |
+-------------------------------------------+
| |
| HCA 4k page |
| |
+-------------------------------------------+
The VA addresses are coming from rdma-core in this diagram can be
arbitrary, but for 64k pages, the VA may be offset by some number of HCA
4k pages and followed by some number of HCA 4k pages.
The current iterator doesn't account for either the preceding 4k pages or
the following 4k pages.
Fix the issue by extending the ib_block_iter to contain the number of DMA
pages like comment [1] says and by using __sg_advance to start the
iterator at the first live HCA page.
The changes are contained in a parallel set of iterator start and next
functions that are umem aware and specific to umem since there is one user
of the rdma_for_each_block() without umem.
These two fixes prevents the extra pages before and after the user MR
data.
Fix the preceding pages by using the __sq_advance field to start at the
first 4k page containing MR data.
Fix the following pages by saving the number of pgsz blocks in the
iterator state and downcounting on each next.
This fix allows for the elimination of the small page crutch noted in the
Fixes.
Fixes: 10c75ccb54e4 ("RDMA/umem: Prevent small pages from being returned by ib_umem_find_best_pgsz()")
Link: https://lore.kernel.org/r/20231129202143.1434-2-shiraz.saleem@intel.com
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3d99ed60721bf2e108c8fc660775766057689a92 ]
Similar to other protocol ops, it's useful for an scmi module driver to get
some generic information of a performance domain. Therefore, let's add a
new callback to provide this information. The information is currently
limited to the name of the performance domain and whether the set-level
operation is supported, although this can easily be extended if we find the
need for it.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20230825112633.236607-3-ulf.hansson@linaro.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Stable-dep-of: 8e3c98d9187e ("firmware: arm_scmi: Fix frequency truncation by promoting multiplier type")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e9090e70e618cd62ab7bf2914511e5eea31a2535 ]
Similar to other protocol ops, it's useful for an scmi module driver to get
the number of supported performance domains, hence let's make this
available by adding a new perf protocol callback. Note that, a user is
being added from subsequent changes.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20230825112633.236607-2-ulf.hansson@linaro.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Stable-dep-of: 8e3c98d9187e ("firmware: arm_scmi: Fix frequency truncation by promoting multiplier type")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e03781879a0d524ce3126678d50a80484a513c4b ]
The "NET_DM" generic netlink family notifies drop locations over the
"events" multicast group. This is problematic since by default generic
netlink allows non-root users to listen to these notifications.
Fix by adding a new field to the generic netlink multicast group
structure that when set prevents non-root users or root without the
'CAP_SYS_ADMIN' capability (in the user namespace owning the network
namespace) from joining the group. Set this field for the "events"
group. Use 'CAP_SYS_ADMIN' rather than 'CAP_NET_ADMIN' because of the
nature of the information that is shared over this group.
Note that the capability check in this case will always be performed
against the initial user namespace since the family is not netns aware
and only operates in the initial network namespace.
A new field is added to the structure rather than using the "flags"
field because the existing field uses uAPI flags and it is inappropriate
to add a new uAPI flag for an internal kernel check. In net-next we can
rework the "flags" field to use internal flags and fold the new field
into it. But for now, in order to reduce the amount of changes, add a
new field.
Since the information can only be consumed by root, mark the control
plane operations that start and stop the tracing as root-only using the
'GENL_ADMIN_PERM' flag.
Tested using [1].
Before:
# capsh -- -c ./dm_repo
# capsh --drop=cap_sys_admin -- -c ./dm_repo
After:
# capsh -- -c ./dm_repo
# capsh --drop=cap_sys_admin -- -c ./dm_repo
Failed to join "events" multicast group
[1]
$ cat dm.c
#include <stdio.h>
#include <netlink/genl/ctrl.h>
#include <netlink/genl/genl.h>
#include <netlink/socket.h>
int main(int argc, char **argv)
{
struct nl_sock *sk;
int grp, err;
sk = nl_socket_alloc();
if (!sk) {
fprintf(stderr, "Failed to allocate socket\n");
return -1;
}
err = genl_connect(sk);
if (err) {
fprintf(stderr, "Failed to connect socket\n");
return err;
}
grp = genl_ctrl_resolve_grp(sk, "NET_DM", "events");
if (grp < 0) {
fprintf(stderr,
"Failed to resolve \"events\" multicast group\n");
return grp;
}
err = nl_socket_add_memberships(sk, grp, NFNLGRP_NONE);
if (err) {
fprintf(stderr, "Failed to join \"events\" multicast group\n");
return err;
}
return 0;
}
$ gcc -I/usr/include/libnl3 -lnl-3 -lnl-genl-3 -o dm_repo dm.c
Fixes: 9a8afc8d3962 ("Network Drop Monitor: Adding drop monitor implementation & Netlink protocol")
Reported-by: "The UK's National Cyber Security Centre (NCSC)" <security@ncsc.gov.uk>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20231206213102.1824398-3-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 58d3aade20cdddbac6c9707ac0f3f5f8c1278b74 ]
After the blamed commit below, if the user-space application performs
window clamping when tp->rcv_wnd is 0, the TCP socket will never be
able to announce a non 0 receive window, even after completely emptying
the receive buffer and re-setting the window clamp to higher values.
Refactor tcp_set_window_clamp() to address the issue: when the user
decreases the current clamp value, set rcv_ssthresh according to the
same logic used at buffer initialization, but ensuring reserved mem
provisioning.
To avoid code duplication factor-out the relevant bits from
tcp_adjust_rcv_ssthresh() in a new helper and reuse it in the above
scenario.
When increasing the clamp value, give the rcv_ssthresh a chance to grow
according to previously implemented heuristic.
Fixes: 3aa7857fe1d7 ("tcp: enable mid stream window clamp")
Reported-by: David Gibson <david@gibson.dropbear.id.au>
Reported-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/705dad54e6e6e9a010e571bf58e0b35a8ae70503.1701706073.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>