The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.14.y
git checkout FETCH_HEAD
git cherry-pick -x 597441b3436a43011f31ce71dc0a6c0bf5ce958a
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2023052843-pants-drearily-a496@gregkh' --subject-prefix 'PATCH 4.14.y' HEAD^..
Possible dependencies:
597441b3436a ("btrfs: use nofs when cleaning up aborted transactions")
fe816d0f1d4c ("btrfs: Fix delalloc inodes invalidation during transaction abort")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 597441b3436a43011f31ce71dc0a6c0bf5ce958a Mon Sep 17 00:00:00 2001
From: Josef Bacik <josef(a)toxicpanda.com>
Date: Thu, 11 May 2023 12:45:59 -0400
Subject: [PATCH] btrfs: use nofs when cleaning up aborted transactions
Our CI system caught a lockdep splat:
======================================================
WARNING: possible circular locking dependency detected
6.3.0-rc7+ #1167 Not tainted
------------------------------------------------------
kswapd0/46 is trying to acquire lock:
ffff8c6543abd650 (sb_internal#2){++++}-{0:0}, at: btrfs_commit_inode_delayed_inode+0x5f/0x120
but task is already holding lock:
ffffffffabe61b40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x4aa/0x7a0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (fs_reclaim){+.+.}-{0:0}:
fs_reclaim_acquire+0xa5/0xe0
kmem_cache_alloc+0x31/0x2c0
alloc_extent_state+0x1d/0xd0
__clear_extent_bit+0x2e0/0x4f0
try_release_extent_mapping+0x216/0x280
btrfs_release_folio+0x2e/0x90
invalidate_inode_pages2_range+0x397/0x470
btrfs_cleanup_dirty_bgs+0x9e/0x210
btrfs_cleanup_one_transaction+0x22/0x760
btrfs_commit_transaction+0x3b7/0x13a0
create_subvol+0x59b/0x970
btrfs_mksubvol+0x435/0x4f0
__btrfs_ioctl_snap_create+0x11e/0x1b0
btrfs_ioctl_snap_create_v2+0xbf/0x140
btrfs_ioctl+0xa45/0x28f0
__x64_sys_ioctl+0x88/0xc0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
-> #0 (sb_internal#2){++++}-{0:0}:
__lock_acquire+0x1435/0x21a0
lock_acquire+0xc2/0x2b0
start_transaction+0x401/0x730
btrfs_commit_inode_delayed_inode+0x5f/0x120
btrfs_evict_inode+0x292/0x3d0
evict+0xcc/0x1d0
inode_lru_isolate+0x14d/0x1e0
__list_lru_walk_one+0xbe/0x1c0
list_lru_walk_one+0x58/0x80
prune_icache_sb+0x39/0x60
super_cache_scan+0x161/0x1f0
do_shrink_slab+0x163/0x340
shrink_slab+0x1d3/0x290
shrink_node+0x300/0x720
balance_pgdat+0x35c/0x7a0
kswapd+0x205/0x410
kthread+0xf0/0x120
ret_from_fork+0x29/0x50
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(fs_reclaim);
lock(sb_internal#2);
lock(fs_reclaim);
lock(sb_internal#2);
*** DEADLOCK ***
3 locks held by kswapd0/46:
#0: ffffffffabe61b40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x4aa/0x7a0
#1: ffffffffabe50270 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0x113/0x290
#2: ffff8c6543abd0e0 (&type->s_umount_key#44){++++}-{3:3}, at: super_cache_scan+0x38/0x1f0
stack backtrace:
CPU: 0 PID: 46 Comm: kswapd0 Not tainted 6.3.0-rc7+ #1167
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x58/0x90
check_noncircular+0xd6/0x100
? save_trace+0x3f/0x310
? add_lock_to_list+0x97/0x120
__lock_acquire+0x1435/0x21a0
lock_acquire+0xc2/0x2b0
? btrfs_commit_inode_delayed_inode+0x5f/0x120
start_transaction+0x401/0x730
? btrfs_commit_inode_delayed_inode+0x5f/0x120
btrfs_commit_inode_delayed_inode+0x5f/0x120
btrfs_evict_inode+0x292/0x3d0
? lock_release+0x134/0x270
? __pfx_wake_bit_function+0x10/0x10
evict+0xcc/0x1d0
inode_lru_isolate+0x14d/0x1e0
__list_lru_walk_one+0xbe/0x1c0
? __pfx_inode_lru_isolate+0x10/0x10
? __pfx_inode_lru_isolate+0x10/0x10
list_lru_walk_one+0x58/0x80
prune_icache_sb+0x39/0x60
super_cache_scan+0x161/0x1f0
do_shrink_slab+0x163/0x340
shrink_slab+0x1d3/0x290
shrink_node+0x300/0x720
balance_pgdat+0x35c/0x7a0
kswapd+0x205/0x410
? __pfx_autoremove_wake_function+0x10/0x10
? __pfx_kswapd+0x10/0x10
kthread+0xf0/0x120
? __pfx_kthread+0x10/0x10
ret_from_fork+0x29/0x50
</TASK>
This happens because when we abort the transaction in the transaction
commit path we call invalidate_inode_pages2_range on our block group
cache inodes (if we have space cache v1) and any delalloc inodes we may
have. The plain invalidate_inode_pages2_range() call passes through
GFP_KERNEL, which makes sense in most cases, but not here. Wrap these
two invalidate callees with memalloc_nofs_save/memalloc_nofs_restore to
make sure we don't end up with the fs reclaim dependency under the
transaction dependency.
CC: stable(a)vger.kernel.org # 4.14+
Signed-off-by: Josef Bacik <josef(a)toxicpanda.com>
Reviewed-by: David Sterba <dsterba(a)suse.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index fbf9006c6234..6de6dcf2743e 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -4936,7 +4936,11 @@ static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
*/
inode = igrab(&btrfs_inode->vfs_inode);
if (inode) {
+ unsigned int nofs_flag;
+
+ nofs_flag = memalloc_nofs_save();
invalidate_inode_pages2(inode->i_mapping);
+ memalloc_nofs_restore(nofs_flag);
iput(inode);
}
spin_lock(&root->delalloc_lock);
@@ -5042,7 +5046,12 @@ static void btrfs_cleanup_bg_io(struct btrfs_block_group *cache)
inode = cache->io_ctl.inode;
if (inode) {
+ unsigned int nofs_flag;
+
+ nofs_flag = memalloc_nofs_save();
invalidate_inode_pages2(inode->i_mapping);
+ memalloc_nofs_restore(nofs_flag);
+
BTRFS_I(inode)->generation = 0;
cache->io_ctl.inode = NULL;
iput(inode);
Partially backport v6.3 commit 11f75a01448f ("selftests/memfd: add
tests for MFD_NOEXEC_SEAL MFD_EXEC") to fix an unknown type name
build error.
In some systems, the __u64 typedef is not present due to differences
in system headers, causing compilation errors like this one:
fuse_test.c:64:8: error: unknown type name '__u64'
64 | static __u64 mfd_assert_get_seals(int fd)
This header includes the __u64 typedef which increases the
likelihood of successful compilation on a wider variety of systems.
Signed-off-by: Hardik Garg <hargar(a)linux.microsoft.com>
---
tools/testing/selftests/memfd/fuse_test.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/tools/testing/selftests/memfd/fuse_test.c b/tools/testing/selftests/memfd/fuse_test.c
index be675002f918..93798c8c5d54 100644
--- a/tools/testing/selftests/memfd/fuse_test.c
+++ b/tools/testing/selftests/memfd/fuse_test.c
@@ -22,6 +22,7 @@
#include <linux/falloc.h>
#include <fcntl.h>
#include <linux/memfd.h>
+#include <linux/types.h>
#include <sched.h>
#include <stdio.h>
#include <stdlib.h>
--
2.25.1
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x ce0b15d11ad837fbacc5356941712218e38a0a83
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2023052612-reproach-snowbird-d3a2@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
ce0b15d11ad8 ("x86/mm: Avoid incomplete Global INVLPG flushes")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From ce0b15d11ad837fbacc5356941712218e38a0a83 Mon Sep 17 00:00:00 2001
From: Dave Hansen <dave.hansen(a)linux.intel.com>
Date: Tue, 16 May 2023 12:24:25 -0700
Subject: [PATCH] x86/mm: Avoid incomplete Global INVLPG flushes
The INVLPG instruction is used to invalidate TLB entries for a
specified virtual address. When PCIDs are enabled, INVLPG is supposed
to invalidate TLB entries for the specified address for both the
current PCID *and* Global entries. (Note: Only kernel mappings set
Global=1.)
Unfortunately, some INVLPG implementations can leave Global
translations unflushed when PCIDs are enabled.
As a workaround, never enable PCIDs on affected processors.
I expect there to eventually be microcode mitigations to replace this
software workaround. However, the exact version numbers where that
will happen are not known today. Once the version numbers are set in
stone, the processor list can be tweaked to only disable PCIDs on
affected processors with affected microcode.
Note: if anyone wants a quick fix that doesn't require patching, just
stick 'nopcid' on your kernel command-line.
Signed-off-by: Dave Hansen <dave.hansen(a)linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx(a)linutronix.de>
Cc: stable(a)vger.kernel.org
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 3cdac0f0055d..8192452d1d2d 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -9,6 +9,7 @@
#include <linux/sched/task.h>
#include <asm/set_memory.h>
+#include <asm/cpu_device_id.h>
#include <asm/e820/api.h>
#include <asm/init.h>
#include <asm/page.h>
@@ -261,6 +262,24 @@ static void __init probe_page_size_mask(void)
}
}
+#define INTEL_MATCH(_model) { .vendor = X86_VENDOR_INTEL, \
+ .family = 6, \
+ .model = _model, \
+ }
+/*
+ * INVLPG may not properly flush Global entries
+ * on these CPUs when PCIDs are enabled.
+ */
+static const struct x86_cpu_id invlpg_miss_ids[] = {
+ INTEL_MATCH(INTEL_FAM6_ALDERLAKE ),
+ INTEL_MATCH(INTEL_FAM6_ALDERLAKE_L ),
+ INTEL_MATCH(INTEL_FAM6_ALDERLAKE_N ),
+ INTEL_MATCH(INTEL_FAM6_RAPTORLAKE ),
+ INTEL_MATCH(INTEL_FAM6_RAPTORLAKE_P),
+ INTEL_MATCH(INTEL_FAM6_RAPTORLAKE_S),
+ {}
+};
+
static void setup_pcid(void)
{
if (!IS_ENABLED(CONFIG_X86_64))
@@ -269,6 +288,12 @@ static void setup_pcid(void)
if (!boot_cpu_has(X86_FEATURE_PCID))
return;
+ if (x86_match_cpu(invlpg_miss_ids)) {
+ pr_info("Incomplete global flushes, disabling PCID");
+ setup_clear_cpu_cap(X86_FEATURE_PCID);
+ return;
+ }
+
if (boot_cpu_has(X86_FEATURE_PGE)) {
/*
* This can't be cr4_set_bits_and_update_boot() -- the
Hi Greg, Sasha,
[ This is v2 including two initial missing backport patches and one new
patch at the end of this batch. ]
This is second round of -stable backport fixes for 4.14. This batch
includes dependency patches which are not currently in the 4.14 branch.
The following list shows the backported patches, I am using original
commit IDs for reference:
1) 4f16d25c68ec ("netfilter: nftables: add nft_parse_register_load() and use it")
2) 345023b0db31 ("netfilter: nftables: add nft_parse_register_store() and use it")
3) 08a01c11a5bb ("netfilter: nftables: statify nft_parse_register()")
4) 6e1acfa387b9 ("netfilter: nf_tables: validate registers coming from userspace.")
5) 20a1452c3542 ("netfilter: nf_tables: add nft_setelem_parse_key()")
6) fdb9c405e35b ("netfilter: nf_tables: allow up to 64 bytes in the set element data area")
7) 7e6bc1f6cabc ("netfilter: nf_tables: stricter validation of element data")
8) 215a31f19ded ("netfilter: nft_dynset: do not reject set updates with NFT_SET_EVAL")
9) 36d5b2913219 ("netfilter: nf_tables: do not allow RULE_ID to refer to another chain")
10) 470ee20e069a ("netfilter: nf_tables: do not allow SET_ID to refer to another table")
11) d209df3e7f70 ("netfilter: nf_tables: fix register ordering")
Please, apply.
Thanks.
Florian Westphal (1):
netfilter: nf_tables: fix register ordering
Pablo Neira Ayuso (10):
netfilter: nftables: add nft_parse_register_load() and use it
netfilter: nftables: add nft_parse_register_store() and use it
netfilter: nftables: statify nft_parse_register()
netfilter: nf_tables: validate registers coming from userspace.
netfilter: nf_tables: add nft_setelem_parse_key()
netfilter: nf_tables: allow up to 64 bytes in the set element data area
netfilter: nf_tables: stricter validation of element data
netfilter: nft_dynset: do not reject set updates with NFT_SET_EVAL
netfilter: nf_tables: do not allow RULE_ID to refer to another chain
netfilter: nf_tables: do not allow SET_ID to refer to another table
include/net/netfilter/nf_tables.h | 17 +-
include/net/netfilter/nf_tables_core.h | 14 +-
include/net/netfilter/nft_fib.h | 2 +-
include/net/netfilter/nft_masq.h | 4 +-
include/net/netfilter/nft_meta.h | 4 +-
include/net/netfilter/nft_redir.h | 4 +-
include/uapi/linux/netfilter/nf_tables.h | 2 +-
net/bridge/netfilter/nft_meta_bridge.c | 5 +-
net/ipv4/netfilter/nft_dup_ipv4.c | 18 +-
net/ipv6/netfilter/nft_dup_ipv6.c | 18 +-
net/netfilter/nf_tables_api.c | 220 +++++++++++++++--------
net/netfilter/nft_bitwise.c | 14 +-
net/netfilter/nft_byteorder.c | 14 +-
net/netfilter/nft_cmp.c | 8 +-
net/netfilter/nft_ct.c | 12 +-
net/netfilter/nft_dup_netdev.c | 6 +-
net/netfilter/nft_dynset.c | 16 +-
net/netfilter/nft_exthdr.c | 14 +-
net/netfilter/nft_fib.c | 5 +-
net/netfilter/nft_fwd_netdev.c | 6 +-
net/netfilter/nft_hash.c | 25 ++-
net/netfilter/nft_immediate.c | 8 +-
net/netfilter/nft_lookup.c | 14 +-
net/netfilter/nft_masq.c | 14 +-
net/netfilter/nft_meta.c | 8 +-
net/netfilter/nft_nat.c | 35 ++--
net/netfilter/nft_numgen.c | 15 +-
net/netfilter/nft_objref.c | 6 +-
net/netfilter/nft_payload.c | 10 +-
net/netfilter/nft_queue.c | 12 +-
net/netfilter/nft_range.c | 6 +-
net/netfilter/nft_redir.c | 14 +-
net/netfilter/nft_rt.c | 7 +-
33 files changed, 320 insertions(+), 257 deletions(-)
--
2.30.2
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x d1d8875c8c13517f6fd1ff8d4d3e1ac366a17e07
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2023052834-shakable-mobile-fdb0@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
d1d8875c8c13 ("binder: fix UAF of alloc->vma in race with munmap()")
c0fd2101781e ("Revert "android: binder: stop saving a pointer to the VMA"")
7b0dbd940765 ("binder: fix binder_alloc kernel-doc warnings")
d6d04d71daae ("binder: remove binder_alloc_set_vma()")
e66b77e50522 ("binder: rename alloc->vma_vm_mm to alloc->mm")
50e177c5bfd9 ("Merge 6.0-rc4 into char-misc-next")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From d1d8875c8c13517f6fd1ff8d4d3e1ac366a17e07 Mon Sep 17 00:00:00 2001
From: Carlos Llamas <cmllamas(a)google.com>
Date: Fri, 19 May 2023 19:59:49 +0000
Subject: [PATCH] binder: fix UAF of alloc->vma in race with munmap()
[ cmllamas: clean forward port from commit 015ac18be7de ("binder: fix
UAF of alloc->vma in race with munmap()") in 5.10 stable. It is needed
in mainline after the revert of commit a43cfc87caaf ("android: binder:
stop saving a pointer to the VMA") as pointed out by Liam. The commit
log and tags have been tweaked to reflect this. ]
In commit 720c24192404 ("ANDROID: binder: change down_write to
down_read") binder assumed the mmap read lock is sufficient to protect
alloc->vma inside binder_update_page_range(). This used to be accurate
until commit dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in
munmap"), which now downgrades the mmap_lock after detaching the vma
from the rbtree in munmap(). Then it proceeds to teardown and free the
vma with only the read lock held.
This means that accesses to alloc->vma in binder_update_page_range() now
will race with vm_area_free() in munmap() and can cause a UAF as shown
in the following KASAN trace:
==================================================================
BUG: KASAN: use-after-free in vm_insert_page+0x7c/0x1f0
Read of size 8 at addr ffff16204ad00600 by task server/558
CPU: 3 PID: 558 Comm: server Not tainted 5.10.150-00001-gdc8dcf942daa #1
Hardware name: linux,dummy-virt (DT)
Call trace:
dump_backtrace+0x0/0x2a0
show_stack+0x18/0x2c
dump_stack+0xf8/0x164
print_address_description.constprop.0+0x9c/0x538
kasan_report+0x120/0x200
__asan_load8+0xa0/0xc4
vm_insert_page+0x7c/0x1f0
binder_update_page_range+0x278/0x50c
binder_alloc_new_buf+0x3f0/0xba0
binder_transaction+0x64c/0x3040
binder_thread_write+0x924/0x2020
binder_ioctl+0x1610/0x2e5c
__arm64_sys_ioctl+0xd4/0x120
el0_svc_common.constprop.0+0xac/0x270
do_el0_svc+0x38/0xa0
el0_svc+0x1c/0x2c
el0_sync_handler+0xe8/0x114
el0_sync+0x180/0x1c0
Allocated by task 559:
kasan_save_stack+0x38/0x6c
__kasan_kmalloc.constprop.0+0xe4/0xf0
kasan_slab_alloc+0x18/0x2c
kmem_cache_alloc+0x1b0/0x2d0
vm_area_alloc+0x28/0x94
mmap_region+0x378/0x920
do_mmap+0x3f0/0x600
vm_mmap_pgoff+0x150/0x17c
ksys_mmap_pgoff+0x284/0x2dc
__arm64_sys_mmap+0x84/0xa4
el0_svc_common.constprop.0+0xac/0x270
do_el0_svc+0x38/0xa0
el0_svc+0x1c/0x2c
el0_sync_handler+0xe8/0x114
el0_sync+0x180/0x1c0
Freed by task 560:
kasan_save_stack+0x38/0x6c
kasan_set_track+0x28/0x40
kasan_set_free_info+0x24/0x4c
__kasan_slab_free+0x100/0x164
kasan_slab_free+0x14/0x20
kmem_cache_free+0xc4/0x34c
vm_area_free+0x1c/0x2c
remove_vma+0x7c/0x94
__do_munmap+0x358/0x710
__vm_munmap+0xbc/0x130
__arm64_sys_munmap+0x4c/0x64
el0_svc_common.constprop.0+0xac/0x270
do_el0_svc+0x38/0xa0
el0_svc+0x1c/0x2c
el0_sync_handler+0xe8/0x114
el0_sync+0x180/0x1c0
[...]
==================================================================
To prevent the race above, revert back to taking the mmap write lock
inside binder_update_page_range(). One might expect an increase of mmap
lock contention. However, binder already serializes these calls via top
level alloc->mutex. Also, there was no performance impact shown when
running the binder benchmark tests.
Fixes: c0fd2101781e ("Revert "android: binder: stop saving a pointer to the VMA"")
Fixes: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap")
Reported-by: Jann Horn <jannh(a)google.com>
Closes: https://lore.kernel.org/all/20230518144052.xkj6vmddccq4v66b@revolver
Cc: <stable(a)vger.kernel.org>
Cc: Minchan Kim <minchan(a)kernel.org>
Cc: Yang Shi <yang.shi(a)linux.alibaba.com>
Cc: Liam Howlett <liam.howlett(a)oracle.com>
Signed-off-by: Carlos Llamas <cmllamas(a)google.com>
Acked-by: Todd Kjos <tkjos(a)google.com>
Link: https://lore.kernel.org/r/20230519195950.1775656-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index e7c9d466f8e8..662a2a2e2e84 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -212,7 +212,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
mm = alloc->mm;
if (mm) {
- mmap_read_lock(mm);
+ mmap_write_lock(mm);
vma = alloc->vma;
}
@@ -270,7 +270,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
trace_binder_alloc_page_end(alloc, index);
}
if (mm) {
- mmap_read_unlock(mm);
+ mmap_write_unlock(mm);
mmput(mm);
}
return 0;
@@ -303,7 +303,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
}
err_no_vma:
if (mm) {
- mmap_read_unlock(mm);
+ mmap_write_unlock(mm);
mmput(mm);
}
return vma ? -ENOMEM : -ESRCH;
The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x d1d8875c8c13517f6fd1ff8d4d3e1ac366a17e07
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2023052832-opposing-flavoring-f084@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
d1d8875c8c13 ("binder: fix UAF of alloc->vma in race with munmap()")
c0fd2101781e ("Revert "android: binder: stop saving a pointer to the VMA"")
7b0dbd940765 ("binder: fix binder_alloc kernel-doc warnings")
d6d04d71daae ("binder: remove binder_alloc_set_vma()")
e66b77e50522 ("binder: rename alloc->vma_vm_mm to alloc->mm")
50e177c5bfd9 ("Merge 6.0-rc4 into char-misc-next")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From d1d8875c8c13517f6fd1ff8d4d3e1ac366a17e07 Mon Sep 17 00:00:00 2001
From: Carlos Llamas <cmllamas(a)google.com>
Date: Fri, 19 May 2023 19:59:49 +0000
Subject: [PATCH] binder: fix UAF of alloc->vma in race with munmap()
[ cmllamas: clean forward port from commit 015ac18be7de ("binder: fix
UAF of alloc->vma in race with munmap()") in 5.10 stable. It is needed
in mainline after the revert of commit a43cfc87caaf ("android: binder:
stop saving a pointer to the VMA") as pointed out by Liam. The commit
log and tags have been tweaked to reflect this. ]
In commit 720c24192404 ("ANDROID: binder: change down_write to
down_read") binder assumed the mmap read lock is sufficient to protect
alloc->vma inside binder_update_page_range(). This used to be accurate
until commit dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in
munmap"), which now downgrades the mmap_lock after detaching the vma
from the rbtree in munmap(). Then it proceeds to teardown and free the
vma with only the read lock held.
This means that accesses to alloc->vma in binder_update_page_range() now
will race with vm_area_free() in munmap() and can cause a UAF as shown
in the following KASAN trace:
==================================================================
BUG: KASAN: use-after-free in vm_insert_page+0x7c/0x1f0
Read of size 8 at addr ffff16204ad00600 by task server/558
CPU: 3 PID: 558 Comm: server Not tainted 5.10.150-00001-gdc8dcf942daa #1
Hardware name: linux,dummy-virt (DT)
Call trace:
dump_backtrace+0x0/0x2a0
show_stack+0x18/0x2c
dump_stack+0xf8/0x164
print_address_description.constprop.0+0x9c/0x538
kasan_report+0x120/0x200
__asan_load8+0xa0/0xc4
vm_insert_page+0x7c/0x1f0
binder_update_page_range+0x278/0x50c
binder_alloc_new_buf+0x3f0/0xba0
binder_transaction+0x64c/0x3040
binder_thread_write+0x924/0x2020
binder_ioctl+0x1610/0x2e5c
__arm64_sys_ioctl+0xd4/0x120
el0_svc_common.constprop.0+0xac/0x270
do_el0_svc+0x38/0xa0
el0_svc+0x1c/0x2c
el0_sync_handler+0xe8/0x114
el0_sync+0x180/0x1c0
Allocated by task 559:
kasan_save_stack+0x38/0x6c
__kasan_kmalloc.constprop.0+0xe4/0xf0
kasan_slab_alloc+0x18/0x2c
kmem_cache_alloc+0x1b0/0x2d0
vm_area_alloc+0x28/0x94
mmap_region+0x378/0x920
do_mmap+0x3f0/0x600
vm_mmap_pgoff+0x150/0x17c
ksys_mmap_pgoff+0x284/0x2dc
__arm64_sys_mmap+0x84/0xa4
el0_svc_common.constprop.0+0xac/0x270
do_el0_svc+0x38/0xa0
el0_svc+0x1c/0x2c
el0_sync_handler+0xe8/0x114
el0_sync+0x180/0x1c0
Freed by task 560:
kasan_save_stack+0x38/0x6c
kasan_set_track+0x28/0x40
kasan_set_free_info+0x24/0x4c
__kasan_slab_free+0x100/0x164
kasan_slab_free+0x14/0x20
kmem_cache_free+0xc4/0x34c
vm_area_free+0x1c/0x2c
remove_vma+0x7c/0x94
__do_munmap+0x358/0x710
__vm_munmap+0xbc/0x130
__arm64_sys_munmap+0x4c/0x64
el0_svc_common.constprop.0+0xac/0x270
do_el0_svc+0x38/0xa0
el0_svc+0x1c/0x2c
el0_sync_handler+0xe8/0x114
el0_sync+0x180/0x1c0
[...]
==================================================================
To prevent the race above, revert back to taking the mmap write lock
inside binder_update_page_range(). One might expect an increase of mmap
lock contention. However, binder already serializes these calls via top
level alloc->mutex. Also, there was no performance impact shown when
running the binder benchmark tests.
Fixes: c0fd2101781e ("Revert "android: binder: stop saving a pointer to the VMA"")
Fixes: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap")
Reported-by: Jann Horn <jannh(a)google.com>
Closes: https://lore.kernel.org/all/20230518144052.xkj6vmddccq4v66b@revolver
Cc: <stable(a)vger.kernel.org>
Cc: Minchan Kim <minchan(a)kernel.org>
Cc: Yang Shi <yang.shi(a)linux.alibaba.com>
Cc: Liam Howlett <liam.howlett(a)oracle.com>
Signed-off-by: Carlos Llamas <cmllamas(a)google.com>
Acked-by: Todd Kjos <tkjos(a)google.com>
Link: https://lore.kernel.org/r/20230519195950.1775656-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index e7c9d466f8e8..662a2a2e2e84 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -212,7 +212,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
mm = alloc->mm;
if (mm) {
- mmap_read_lock(mm);
+ mmap_write_lock(mm);
vma = alloc->vma;
}
@@ -270,7 +270,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
trace_binder_alloc_page_end(alloc, index);
}
if (mm) {
- mmap_read_unlock(mm);
+ mmap_write_unlock(mm);
mmput(mm);
}
return 0;
@@ -303,7 +303,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
}
err_no_vma:
if (mm) {
- mmap_read_unlock(mm);
+ mmap_write_unlock(mm);
mmput(mm);
}
return vma ? -ENOMEM : -ESRCH;
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x d1d8875c8c13517f6fd1ff8d4d3e1ac366a17e07
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2023052830-unblended-envision-4bbd@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
d1d8875c8c13 ("binder: fix UAF of alloc->vma in race with munmap()")
c0fd2101781e ("Revert "android: binder: stop saving a pointer to the VMA"")
7b0dbd940765 ("binder: fix binder_alloc kernel-doc warnings")
d6d04d71daae ("binder: remove binder_alloc_set_vma()")
e66b77e50522 ("binder: rename alloc->vma_vm_mm to alloc->mm")
50e177c5bfd9 ("Merge 6.0-rc4 into char-misc-next")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From d1d8875c8c13517f6fd1ff8d4d3e1ac366a17e07 Mon Sep 17 00:00:00 2001
From: Carlos Llamas <cmllamas(a)google.com>
Date: Fri, 19 May 2023 19:59:49 +0000
Subject: [PATCH] binder: fix UAF of alloc->vma in race with munmap()
[ cmllamas: clean forward port from commit 015ac18be7de ("binder: fix
UAF of alloc->vma in race with munmap()") in 5.10 stable. It is needed
in mainline after the revert of commit a43cfc87caaf ("android: binder:
stop saving a pointer to the VMA") as pointed out by Liam. The commit
log and tags have been tweaked to reflect this. ]
In commit 720c24192404 ("ANDROID: binder: change down_write to
down_read") binder assumed the mmap read lock is sufficient to protect
alloc->vma inside binder_update_page_range(). This used to be accurate
until commit dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in
munmap"), which now downgrades the mmap_lock after detaching the vma
from the rbtree in munmap(). Then it proceeds to teardown and free the
vma with only the read lock held.
This means that accesses to alloc->vma in binder_update_page_range() now
will race with vm_area_free() in munmap() and can cause a UAF as shown
in the following KASAN trace:
==================================================================
BUG: KASAN: use-after-free in vm_insert_page+0x7c/0x1f0
Read of size 8 at addr ffff16204ad00600 by task server/558
CPU: 3 PID: 558 Comm: server Not tainted 5.10.150-00001-gdc8dcf942daa #1
Hardware name: linux,dummy-virt (DT)
Call trace:
dump_backtrace+0x0/0x2a0
show_stack+0x18/0x2c
dump_stack+0xf8/0x164
print_address_description.constprop.0+0x9c/0x538
kasan_report+0x120/0x200
__asan_load8+0xa0/0xc4
vm_insert_page+0x7c/0x1f0
binder_update_page_range+0x278/0x50c
binder_alloc_new_buf+0x3f0/0xba0
binder_transaction+0x64c/0x3040
binder_thread_write+0x924/0x2020
binder_ioctl+0x1610/0x2e5c
__arm64_sys_ioctl+0xd4/0x120
el0_svc_common.constprop.0+0xac/0x270
do_el0_svc+0x38/0xa0
el0_svc+0x1c/0x2c
el0_sync_handler+0xe8/0x114
el0_sync+0x180/0x1c0
Allocated by task 559:
kasan_save_stack+0x38/0x6c
__kasan_kmalloc.constprop.0+0xe4/0xf0
kasan_slab_alloc+0x18/0x2c
kmem_cache_alloc+0x1b0/0x2d0
vm_area_alloc+0x28/0x94
mmap_region+0x378/0x920
do_mmap+0x3f0/0x600
vm_mmap_pgoff+0x150/0x17c
ksys_mmap_pgoff+0x284/0x2dc
__arm64_sys_mmap+0x84/0xa4
el0_svc_common.constprop.0+0xac/0x270
do_el0_svc+0x38/0xa0
el0_svc+0x1c/0x2c
el0_sync_handler+0xe8/0x114
el0_sync+0x180/0x1c0
Freed by task 560:
kasan_save_stack+0x38/0x6c
kasan_set_track+0x28/0x40
kasan_set_free_info+0x24/0x4c
__kasan_slab_free+0x100/0x164
kasan_slab_free+0x14/0x20
kmem_cache_free+0xc4/0x34c
vm_area_free+0x1c/0x2c
remove_vma+0x7c/0x94
__do_munmap+0x358/0x710
__vm_munmap+0xbc/0x130
__arm64_sys_munmap+0x4c/0x64
el0_svc_common.constprop.0+0xac/0x270
do_el0_svc+0x38/0xa0
el0_svc+0x1c/0x2c
el0_sync_handler+0xe8/0x114
el0_sync+0x180/0x1c0
[...]
==================================================================
To prevent the race above, revert back to taking the mmap write lock
inside binder_update_page_range(). One might expect an increase of mmap
lock contention. However, binder already serializes these calls via top
level alloc->mutex. Also, there was no performance impact shown when
running the binder benchmark tests.
Fixes: c0fd2101781e ("Revert "android: binder: stop saving a pointer to the VMA"")
Fixes: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap")
Reported-by: Jann Horn <jannh(a)google.com>
Closes: https://lore.kernel.org/all/20230518144052.xkj6vmddccq4v66b@revolver
Cc: <stable(a)vger.kernel.org>
Cc: Minchan Kim <minchan(a)kernel.org>
Cc: Yang Shi <yang.shi(a)linux.alibaba.com>
Cc: Liam Howlett <liam.howlett(a)oracle.com>
Signed-off-by: Carlos Llamas <cmllamas(a)google.com>
Acked-by: Todd Kjos <tkjos(a)google.com>
Link: https://lore.kernel.org/r/20230519195950.1775656-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index e7c9d466f8e8..662a2a2e2e84 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -212,7 +212,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
mm = alloc->mm;
if (mm) {
- mmap_read_lock(mm);
+ mmap_write_lock(mm);
vma = alloc->vma;
}
@@ -270,7 +270,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
trace_binder_alloc_page_end(alloc, index);
}
if (mm) {
- mmap_read_unlock(mm);
+ mmap_write_unlock(mm);
mmput(mm);
}
return 0;
@@ -303,7 +303,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
}
err_no_vma:
if (mm) {
- mmap_read_unlock(mm);
+ mmap_write_unlock(mm);
mmput(mm);
}
return vma ? -ENOMEM : -ESRCH;
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x bdc1c5fac982845a58d28690cdb56db8c88a530d
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2023052804-exploit-passion-ce51@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
bdc1c5fac982 ("binder: fix UAF caused by faulty buffer cleanup")
9864bb480133 ("Binder: add TF_UPDATE_TXN to replace outdated txn")
32e9f56a96d8 ("binder: don't detect sender/target during buffer cleanup")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From bdc1c5fac982845a58d28690cdb56db8c88a530d Mon Sep 17 00:00:00 2001
From: Carlos Llamas <cmllamas(a)google.com>
Date: Fri, 5 May 2023 20:30:20 +0000
Subject: [PATCH] binder: fix UAF caused by faulty buffer cleanup
In binder_transaction_buffer_release() the 'failed_at' offset indicates
the number of objects to clean up. However, this function was changed by
commit 44d8047f1d87 ("binder: use standard functions to allocate fds"),
to release all the objects in the buffer when 'failed_at' is zero.
This introduced an issue when a transaction buffer is released without
any objects having been processed so far. In this case, 'failed_at' is
indeed zero yet it is misinterpreted as releasing the entire buffer.
This leads to use-after-free errors where nodes are incorrectly freed
and subsequently accessed. Such is the case in the following KASAN
report:
==================================================================
BUG: KASAN: slab-use-after-free in binder_thread_read+0xc40/0x1f30
Read of size 8 at addr ffff4faf037cfc58 by task poc/474
CPU: 6 PID: 474 Comm: poc Not tainted 6.3.0-12570-g7df047b3f0aa #5
Hardware name: linux,dummy-virt (DT)
Call trace:
dump_backtrace+0x94/0xec
show_stack+0x18/0x24
dump_stack_lvl+0x48/0x60
print_report+0xf8/0x5b8
kasan_report+0xb8/0xfc
__asan_load8+0x9c/0xb8
binder_thread_read+0xc40/0x1f30
binder_ioctl+0xd9c/0x1768
__arm64_sys_ioctl+0xd4/0x118
invoke_syscall+0x60/0x188
[...]
Allocated by task 474:
kasan_save_stack+0x3c/0x64
kasan_set_track+0x2c/0x40
kasan_save_alloc_info+0x24/0x34
__kasan_kmalloc+0xb8/0xbc
kmalloc_trace+0x48/0x5c
binder_new_node+0x3c/0x3a4
binder_transaction+0x2b58/0x36f0
binder_thread_write+0x8e0/0x1b78
binder_ioctl+0x14a0/0x1768
__arm64_sys_ioctl+0xd4/0x118
invoke_syscall+0x60/0x188
[...]
Freed by task 475:
kasan_save_stack+0x3c/0x64
kasan_set_track+0x2c/0x40
kasan_save_free_info+0x38/0x5c
__kasan_slab_free+0xe8/0x154
__kmem_cache_free+0x128/0x2bc
kfree+0x58/0x70
binder_dec_node_tmpref+0x178/0x1fc
binder_transaction_buffer_release+0x430/0x628
binder_transaction+0x1954/0x36f0
binder_thread_write+0x8e0/0x1b78
binder_ioctl+0x14a0/0x1768
__arm64_sys_ioctl+0xd4/0x118
invoke_syscall+0x60/0x188
[...]
==================================================================
In order to avoid these issues, let's always calculate the intended
'failed_at' offset beforehand. This is renamed and wrapped in a helper
function to make it clear and convenient.
Fixes: 32e9f56a96d8 ("binder: don't detect sender/target during buffer cleanup")
Reported-by: Zi Fan Tan <zifantan(a)google.com>
Cc: stable(a)vger.kernel.org
Signed-off-by: Carlos Llamas <cmllamas(a)google.com>
Acked-by: Todd Kjos <tkjos(a)google.com>
Link: https://lore.kernel.org/r/20230505203020.4101154-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index fb56bfc45096..8fb7672021ee 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -1934,24 +1934,23 @@ static void binder_deferred_fd_close(int fd)
static void binder_transaction_buffer_release(struct binder_proc *proc,
struct binder_thread *thread,
struct binder_buffer *buffer,
- binder_size_t failed_at,
+ binder_size_t off_end_offset,
bool is_failure)
{
int debug_id = buffer->debug_id;
- binder_size_t off_start_offset, buffer_offset, off_end_offset;
+ binder_size_t off_start_offset, buffer_offset;
binder_debug(BINDER_DEBUG_TRANSACTION,
"%d buffer release %d, size %zd-%zd, failed at %llx\n",
proc->pid, buffer->debug_id,
buffer->data_size, buffer->offsets_size,
- (unsigned long long)failed_at);
+ (unsigned long long)off_end_offset);
if (buffer->target_node)
binder_dec_node(buffer->target_node, 1, 0);
off_start_offset = ALIGN(buffer->data_size, sizeof(void *));
- off_end_offset = is_failure && failed_at ? failed_at :
- off_start_offset + buffer->offsets_size;
+
for (buffer_offset = off_start_offset; buffer_offset < off_end_offset;
buffer_offset += sizeof(binder_size_t)) {
struct binder_object_header *hdr;
@@ -2111,6 +2110,21 @@ static void binder_transaction_buffer_release(struct binder_proc *proc,
}
}
+/* Clean up all the objects in the buffer */
+static inline void binder_release_entire_buffer(struct binder_proc *proc,
+ struct binder_thread *thread,
+ struct binder_buffer *buffer,
+ bool is_failure)
+{
+ binder_size_t off_end_offset;
+
+ off_end_offset = ALIGN(buffer->data_size, sizeof(void *));
+ off_end_offset += buffer->offsets_size;
+
+ binder_transaction_buffer_release(proc, thread, buffer,
+ off_end_offset, is_failure);
+}
+
static int binder_translate_binder(struct flat_binder_object *fp,
struct binder_transaction *t,
struct binder_thread *thread)
@@ -2806,7 +2820,7 @@ static int binder_proc_transaction(struct binder_transaction *t,
t_outdated->buffer = NULL;
buffer->transaction = NULL;
trace_binder_transaction_update_buffer_release(buffer);
- binder_transaction_buffer_release(proc, NULL, buffer, 0, 0);
+ binder_release_entire_buffer(proc, NULL, buffer, false);
binder_alloc_free_buf(&proc->alloc, buffer);
kfree(t_outdated);
binder_stats_deleted(BINDER_STAT_TRANSACTION);
@@ -3775,7 +3789,7 @@ binder_free_buf(struct binder_proc *proc,
binder_node_inner_unlock(buf_node);
}
trace_binder_transaction_buffer_release(buffer);
- binder_transaction_buffer_release(proc, thread, buffer, 0, is_failure);
+ binder_release_entire_buffer(proc, thread, buffer, is_failure);
binder_alloc_free_buf(&proc->alloc, buffer);
}
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 0fa53349c3acba0239369ba4cd133740a408d246
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2023052832-ideally-gleeful-6ac6@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
0fa53349c3ac ("binder: add lockless binder_alloc_(set|get)_vma()")
c0fd2101781e ("Revert "android: binder: stop saving a pointer to the VMA"")
b15655b12ddc ("Revert "binder_alloc: add missing mmap_lock calls when using the VMA"")
7b0dbd940765 ("binder: fix binder_alloc kernel-doc warnings")
d6d04d71daae ("binder: remove binder_alloc_set_vma()")
e66b77e50522 ("binder: rename alloc->vma_vm_mm to alloc->mm")
50e177c5bfd9 ("Merge 6.0-rc4 into char-misc-next")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0fa53349c3acba0239369ba4cd133740a408d246 Mon Sep 17 00:00:00 2001
From: Carlos Llamas <cmllamas(a)google.com>
Date: Tue, 2 May 2023 20:12:19 +0000
Subject: [PATCH] binder: add lockless binder_alloc_(set|get)_vma()
Bring back the original lockless design in binder_alloc to determine
whether the buffer setup has been completed by the ->mmap() handler.
However, this time use smp_load_acquire() and smp_store_release() to
wrap all the ordering in a single macro call.
Also, add comments to make it evident that binder uses alloc->vma to
determine when the binder_alloc has been fully initialized. In these
scenarios acquiring the mmap_lock is not required.
Fixes: a43cfc87caaf ("android: binder: stop saving a pointer to the VMA")
Cc: Liam Howlett <liam.howlett(a)oracle.com>
Cc: Suren Baghdasaryan <surenb(a)google.com>
Cc: stable(a)vger.kernel.org
Signed-off-by: Carlos Llamas <cmllamas(a)google.com>
Link: https://lore.kernel.org/r/20230502201220.1756319-3-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index eb082b33115b..e7c9d466f8e8 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -309,17 +309,18 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
return vma ? -ENOMEM : -ESRCH;
}
+static inline void binder_alloc_set_vma(struct binder_alloc *alloc,
+ struct vm_area_struct *vma)
+{
+ /* pairs with smp_load_acquire in binder_alloc_get_vma() */
+ smp_store_release(&alloc->vma, vma);
+}
+
static inline struct vm_area_struct *binder_alloc_get_vma(
struct binder_alloc *alloc)
{
- struct vm_area_struct *vma = NULL;
-
- if (alloc->vma) {
- /* Look at description in binder_alloc_set_vma */
- smp_rmb();
- vma = alloc->vma;
- }
- return vma;
+ /* pairs with smp_store_release in binder_alloc_set_vma() */
+ return smp_load_acquire(&alloc->vma);
}
static bool debug_low_async_space_locked(struct binder_alloc *alloc, int pid)
@@ -382,6 +383,7 @@ static struct binder_buffer *binder_alloc_new_buf_locked(
size_t size, data_offsets_size;
int ret;
+ /* Check binder_alloc is fully initialized */
if (!binder_alloc_get_vma(alloc)) {
binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
"%d: binder_alloc_buf, no vma\n",
@@ -777,7 +779,9 @@ int binder_alloc_mmap_handler(struct binder_alloc *alloc,
buffer->free = 1;
binder_insert_free_buffer(alloc, buffer);
alloc->free_async_space = alloc->buffer_size / 2;
- alloc->vma = vma;
+
+ /* Signal binder_alloc is fully initialized */
+ binder_alloc_set_vma(alloc, vma);
return 0;
@@ -959,7 +963,7 @@ int binder_alloc_get_allocated_count(struct binder_alloc *alloc)
*/
void binder_alloc_vma_close(struct binder_alloc *alloc)
{
- alloc->vma = 0;
+ binder_alloc_set_vma(alloc, NULL);
}
/**