In the Linux kernel, the following vulnerability has been resolved:
drm/radeon: Fix integer overflow in radeon_cs_parser_init
The type of size is unsigned, if size is 0x40000000, there will be an
integer overflow, size will be zero after size *= sizeof(uint32_t),
will cause uninitialized memory to be referenced later
In the Linux kernel, the following vulnerability has been resolved:
power: supply: axp288_fuel_gauge: Fix external_power_changed race
fuel_gauge_external_power_changed() dereferences info->bat,
which gets sets in axp288_fuel_gauge_probe() like this:
info->bat = devm_power_supply_register(dev, &fuel_gauge_desc, &psy_cfg);
As soon as devm_power_supply_register() has called device_add()
the external_power_changed callback can get called. So there is a window
where fuel_gauge_external_power_changed() may get called while
info->bat has not been set yet leading to a NULL pointer dereference.
Fixing this is easy. The external_power_changed callback gets passed
the power_supply which will eventually get stored in info->bat,
so fuel_gauge_external_power_changed() can simply directly use
the passed in psy argument which is always valid.
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix use-after-free of nilfs_root in dirtying inodes via iput
During unmount process of nilfs2, nothing holds nilfs_root structure after
nilfs2 detaches its writer in nilfs_detach_log_writer(). Previously,
nilfs_evict_inode() could cause use-after-free read for nilfs_root if
inodes are left in "garbage_list" and released by nilfs_dispose_list at
the end of nilfs_detach_log_writer(), and this bug was fixed by commit
9b5a04ac3ad9 ("nilfs2: fix use-after-free bug of nilfs_root in
nilfs_evict_inode()").
However, it turned out that there is another possibility of UAF in the
call path where mark_inode_dirty_sync() is called from iput():
nilfs_detach_log_writer()
nilfs_dispose_list()
iput()
mark_inode_dirty_sync()
__mark_inode_dirty()
nilfs_dirty_inode()
__nilfs_mark_inode_dirty()
nilfs_load_inode_block() --> causes UAF of nilfs_root struct
This can happen after commit 0ae45f63d4ef ("vfs: add support for a
lazytime mount option"), which changed iput() to call
mark_inode_dirty_sync() on its final reference if i_state has I_DIRTY_TIME
flag and i_nlink is non-zero.
This issue appears after commit 28a65b49eb53 ("nilfs2: do not write dirty
data after degenerating to read-only") when using the syzbot reproducer,
but the issue has potentially existed before.
Fix this issue by adding a "purging flag" to the nilfs structure, setting
that flag while disposing the "garbage_list" and checking it in
__nilfs_mark_inode_dirty().
Unlike commit 9b5a04ac3ad9 ("nilfs2: fix use-after-free bug of nilfs_root
in nilfs_evict_inode()"), this patch does not rely on ns_writer to
determine whether to skip operations, so as not to break recovery on
mount. The nilfs_salvage_orphan_logs routine dirties the buffer of
salvaged data before attaching the log writer, so changing
__nilfs_mark_inode_dirty() to skip the operation when ns_writer is NULL
will cause recovery write to fail. The purpose of using the cleanup-only
flag is to allow for narrowing of such conditions.
In the Linux kernel, the following vulnerability has been resolved:
net: hns: fix possible memory leak in hnae_ae_register()
Inject fault while probing module, if device_register() fails,
but the refcount of kobject is not decreased to 0, the name
allocated in dev_set_name() is leaked. Fix this by calling
put_device(), so that name can be freed in callback function
kobject_cleanup().
unreferenced object 0xffff00c01aba2100 (size 128):
comm "systemd-udevd", pid 1259, jiffies 4294903284 (age 294.152s)
hex dump (first 32 bytes):
68 6e 61 65 30 00 00 00 18 21 ba 1a c0 00 ff ff hnae0....!......
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000034783f26>] slab_post_alloc_hook+0xa0/0x3e0
[<00000000748188f2>] __kmem_cache_alloc_node+0x164/0x2b0
[<00000000ab0743e8>] __kmalloc_node_track_caller+0x6c/0x390
[<000000006c0ffb13>] kvasprintf+0x8c/0x118
[<00000000fa27bfe1>] kvasprintf_const+0x60/0xc8
[<0000000083e10ed7>] kobject_set_name_vargs+0x3c/0xc0
[<000000000b87affc>] dev_set_name+0x7c/0xa0
[<000000003fd8fe26>] hnae_ae_register+0xcc/0x190 [hnae]
[<00000000fe97edc9>] hns_dsaf_ae_init+0x9c/0x108 [hns_dsaf]
[<00000000c36ff1eb>] hns_dsaf_probe+0x548/0x748 [hns_dsaf]
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_set_rbtree: fix overlap expiration walk
The lazy gc on insert that should remove timed-out entries fails to release
the other half of the interval, if any.
Can be reproduced with tests/shell/testcases/sets/0044interval_overlap_0
in nftables.git and kmemleak enabled kernel.
Second bug is the use of rbe_prev vs. prev pointer.
If rbe_prev() returns NULL after at least one iteration, rbe_prev points
to element that is not an end interval, hence it should not be removed.
Lastly, check the genmask of the end interval if this is active in the
current generation.
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix null-ptr-deref in ext4_write_info
I caught a null-ptr-deref bug as follows:
==================================================================
KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f]
CPU: 1 PID: 1589 Comm: umount Not tainted 5.10.0-02219-dirty #339
RIP: 0010:ext4_write_info+0x53/0x1b0
[...]
Call Trace:
dquot_writeback_dquots+0x341/0x9a0
ext4_sync_fs+0x19e/0x800
__sync_filesystem+0x83/0x100
sync_filesystem+0x89/0xf0
generic_shutdown_super+0x79/0x3e0
kill_block_super+0xa1/0x110
deactivate_locked_super+0xac/0x130
deactivate_super+0xb6/0xd0
cleanup_mnt+0x289/0x400
__cleanup_mnt+0x16/0x20
task_work_run+0x11c/0x1c0
exit_to_user_mode_prepare+0x203/0x210
syscall_exit_to_user_mode+0x5b/0x3a0
do_syscall_64+0x59/0x70
entry_SYSCALL_64_after_hwframe+0x44/0xa9
==================================================================
Above issue may happen as follows:
-------------------------------------
exit_to_user_mode_prepare
task_work_run
__cleanup_mnt
cleanup_mnt
deactivate_super
deactivate_locked_super
kill_block_super
generic_shutdown_super
shrink_dcache_for_umount
dentry = sb->s_root
sb->s_root = NULL <--- Here set NULL
sync_filesystem
__sync_filesystem
sb->s_op->sync_fs > ext4_sync_fs
dquot_writeback_dquots
sb->dq_op->write_info > ext4_write_info
ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2)
d_inode(sb->s_root)
s_root->d_inode <--- Null pointer dereference
To solve this problem, we use ext4_journal_start_sb directly
to avoid s_root being used.
In the Linux kernel, the following vulnerability has been resolved:
mmc: rtsx_usb_sdmmc: fix return value check of mmc_add_host()
mmc_add_host() may return error, if we ignore its return value, the memory
that allocated in mmc_alloc_host() will be leaked and it will lead a kernel
crash because of deleting not added device in the remove path.
So fix this by checking the return value and calling mmc_free_host() in the
error path, besides, led_classdev_unregister() and pm_runtime_disable() also
need be called.
In the Linux kernel, the following vulnerability has been resolved:
nfsd: Fix a memory leak in an error handling path
If this memdup_user() call fails, the memory allocated in a previous call
a few lines above should be freed. Otherwise it leaks.
In the Linux kernel, the following vulnerability has been resolved:
misc: tifm: fix possible memory leak in tifm_7xx1_switch_media()
If device_register() returns error in tifm_7xx1_switch_media(),
name of kobject which is allocated in dev_set_name() called in device_add()
is leaked.
Never directly free @dev after calling device_register(), even
if it returned an error! Always use put_device() to give up the
reference initialized.