| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
xfs: do not propagate ENODATA disk errors into xattr code
ENODATA (aka ENOATTR) has a very specific meaning in the xfs xattr code;
namely, that the requested attribute name could not be found.
However, a medium error from disk may also return ENODATA. At best,
this medium error may escape to userspace as "attribute not found"
when in fact it's an IO (disk) error.
At worst, we may oops in xfs_attr_leaf_get() when we do:
error = xfs_attr_leaf_hasname(args, &bp);
if (error == -ENOATTR) {
xfs_trans_brelse(args->trans, bp);
return error;
}
because an ENODATA/ENOATTR error from disk leaves us with a null bp,
and the xfs_trans_brelse will then null-deref it.
As discussed on the list, we really need to modify the lower level
IO functions to trap all disk errors and ensure that we don't let
unique errors like this leak up into higher xfs functions - many
like this should be remapped to EIO.
However, this patch directly addresses a reported bug in the xattr
code, and should be safe to backport to stable kernels. A larger-scope
patch to handle more unique errors at lower levels can follow later.
(Note, prior to 07120f1abdff we did not oops, but we did return the
wrong error code to userspace.) |
| In the Linux kernel, the following vulnerability has been resolved:
drm/msm/dp: Free resources after unregistering them
The DP component's unbind operation walks through the submodules to
unregister and clean things up. But if the unbind happens because the DP
controller itself is being removed, all the memory for those submodules
has just been freed.
Change the order of these operations to avoid the many use-after-free
that otherwise happens in this code path.
Patchwork: https://patchwork.freedesktop.org/patch/542166/ |
| In the Linux kernel, the following vulnerability has been resolved:
drm/msm/dpu: Add a null ptr check for dpu_encoder_needs_modeset
The drm_atomic_get_new_connector_state() can return NULL if the
connector is not part of the atomic state. Add a check to prevent
a NULL pointer dereference.
This follows the same pattern used in dpu_encoder_update_topology()
within the same file, which checks for NULL before using conn_state.
Patchwork: https://patchwork.freedesktop.org/patch/665188/ |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: init quota for 'old.inode' in 'ext4_rename'
Syzbot found the following issue:
ext4_parse_param: s_want_extra_isize=128
ext4_inode_info_init: s_want_extra_isize=32
ext4_rename: old.inode=ffff88823869a2c8 old.dir=ffff888238699828 new.inode=ffff88823869d7e8 new.dir=ffff888238699828
__ext4_mark_inode_dirty: inode=ffff888238699828 ea_isize=32 want_ea_size=128
__ext4_mark_inode_dirty: inode=ffff88823869a2c8 ea_isize=32 want_ea_size=128
ext4_xattr_block_set: inode=ffff88823869a2c8
------------[ cut here ]------------
WARNING: CPU: 13 PID: 2234 at fs/ext4/xattr.c:2070 ext4_xattr_block_set.cold+0x22/0x980
Modules linked in:
RIP: 0010:ext4_xattr_block_set.cold+0x22/0x980
RSP: 0018:ffff888227d3f3b0 EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffff88823007a000 RCX: 0000000000000000
RDX: 0000000000000a03 RSI: 0000000000000040 RDI: ffff888230078178
RBP: 0000000000000000 R08: 000000000000002c R09: ffffed1075c7df8e
R10: ffff8883ae3efc6b R11: ffffed1075c7df8d R12: 0000000000000000
R13: ffff88823869a2c8 R14: ffff8881012e0460 R15: dffffc0000000000
FS: 00007f350ac1f740(0000) GS:ffff8883ae200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f350a6ed6a0 CR3: 0000000237456000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
? ext4_xattr_set_entry+0x3b7/0x2320
? ext4_xattr_block_set+0x0/0x2020
? ext4_xattr_set_entry+0x0/0x2320
? ext4_xattr_check_entries+0x77/0x310
? ext4_xattr_ibody_set+0x23b/0x340
ext4_xattr_move_to_block+0x594/0x720
ext4_expand_extra_isize_ea+0x59a/0x10f0
__ext4_expand_extra_isize+0x278/0x3f0
__ext4_mark_inode_dirty.cold+0x347/0x410
ext4_rename+0xed3/0x174f
vfs_rename+0x13a7/0x2510
do_renameat2+0x55d/0x920
__x64_sys_rename+0x7d/0xb0
do_syscall_64+0x3b/0xa0
entry_SYSCALL_64_after_hwframe+0x72/0xdc
As 'ext4_rename' will modify 'old.inode' ctime and mark inode dirty,
which may trigger expand 'extra_isize' and allocate block. If inode
didn't init quota will lead to warning. To solve above issue, init
'old.inode' firstly in 'ext4_rename'. |
| In the Linux kernel, the following vulnerability has been resolved:
efivarfs: Fix slab-out-of-bounds in efivarfs_d_compare
Observed on kernel 6.6 (present on master as well):
BUG: KASAN: slab-out-of-bounds in memcmp+0x98/0xd0
Call trace:
kasan_check_range+0xe8/0x190
__asan_loadN+0x1c/0x28
memcmp+0x98/0xd0
efivarfs_d_compare+0x68/0xd8
__d_lookup_rcu_op_compare+0x178/0x218
__d_lookup_rcu+0x1f8/0x228
d_alloc_parallel+0x150/0x648
lookup_open.isra.0+0x5f0/0x8d0
open_last_lookups+0x264/0x828
path_openat+0x130/0x3f8
do_filp_open+0x114/0x248
do_sys_openat2+0x340/0x3c0
__arm64_sys_openat+0x120/0x1a0
If dentry->d_name.len < EFI_VARIABLE_GUID_LEN , 'guid' can become
negative, leadings to oob. The issue can be triggered by parallel
lookups using invalid filename:
T1 T2
lookup_open
->lookup
simple_lookup
d_add
// invalid dentry is added to hash list
lookup_open
d_alloc_parallel
__d_lookup_rcu
__d_lookup_rcu_op_compare
hlist_bl_for_each_entry_rcu
// invalid dentry can be retrieved
->d_compare
efivarfs_d_compare
// oob
Fix it by checking 'guid' before cmp. |
| In the Linux kernel, the following vulnerability has been resolved:
net: fix net_dev_start_xmit trace event vs skb_transport_offset()
After blamed commit, we must be more careful about using
skb_transport_offset(), as reminded us by syzbot:
WARNING: CPU: 0 PID: 10 at include/linux/skbuff.h:2868 skb_transport_offset include/linux/skbuff.h:2977 [inline]
WARNING: CPU: 0 PID: 10 at include/linux/skbuff.h:2868 perf_trace_net_dev_start_xmit+0x89a/0xce0 include/trace/events/net.h:14
Modules linked in:
CPU: 0 PID: 10 Comm: kworker/u4:1 Not tainted 6.1.30-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
RIP: 0010:skb_transport_header include/linux/skbuff.h:2868 [inline]
RIP: 0010:skb_transport_offset include/linux/skbuff.h:2977 [inline]
RIP: 0010:perf_trace_net_dev_start_xmit+0x89a/0xce0 include/trace/events/net.h:14
Code: 8b 04 25 28 00 00 00 48 3b 84 24 c0 00 00 00 0f 85 4e 04 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc e8 56 22 01 fd <0f> 0b e9 f6 fc ff ff 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 86 f9 ff
RSP: 0018:ffffc900002bf700 EFLAGS: 00010293
RAX: ffffffff8485d8ca RBX: 000000000000ffff RCX: ffff888100914280
RDX: 0000000000000000 RSI: 000000000000ffff RDI: 000000000000ffff
RBP: ffffc900002bf818 R08: ffffffff8485d5b6 R09: fffffbfff0f8fb5e
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff110217d8f67
R13: ffff88810bec7b3a R14: dffffc0000000000 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8881f6a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f96cf6d52f0 CR3: 000000012224c000 CR4: 0000000000350ef0
Call Trace:
<TASK>
[<ffffffff84715e35>] trace_net_dev_start_xmit include/trace/events/net.h:14 [inline]
[<ffffffff84715e35>] xmit_one net/core/dev.c:3643 [inline]
[<ffffffff84715e35>] dev_hard_start_xmit+0x705/0x980 net/core/dev.c:3660
[<ffffffff8471a232>] __dev_queue_xmit+0x16b2/0x3370 net/core/dev.c:4324
[<ffffffff85416493>] dev_queue_xmit include/linux/netdevice.h:3030 [inline]
[<ffffffff85416493>] batadv_send_skb_packet+0x3f3/0x680 net/batman-adv/send.c:108
[<ffffffff85416744>] batadv_send_broadcast_skb+0x24/0x30 net/batman-adv/send.c:127
[<ffffffff853bc52a>] batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:393 [inline]
[<ffffffff853bc52a>] batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:421 [inline]
[<ffffffff853bc52a>] batadv_iv_send_outstanding_bat_ogm_packet+0x69a/0x840 net/batman-adv/bat_iv_ogm.c:1701
[<ffffffff8151023c>] process_one_work+0x8ac/0x1170 kernel/workqueue.c:2289
[<ffffffff81511938>] worker_thread+0xaa8/0x12d0 kernel/workqueue.c:2436 |
| In the Linux kernel, the following vulnerability has been resolved:
fs/smb: Fix inconsistent refcnt update
A possible inconsistent update of refcount was identified in `smb2_compound_op`.
Such inconsistent update could lead to possible resource leaks.
Why it is a possible bug:
1. In the comment section of the function, it clearly states that the
reference to `cfile` should be dropped after calling this function.
2. Every control flow path would check and drop the reference to
`cfile`, except the patched one.
3. Existing callers would not handle refcount update of `cfile` if
-ENOMEM is returned.
To fix the bug, an extra goto label "out" is added, to make sure that the
cleanup logic would always be respected. As the problem is caused by the
allocation failure of `vars`, the cleanup logic between label "finished"
and "out" can be safely ignored. According to the definition of function
`is_replayable_error`, the error code of "-ENOMEM" is not recoverable.
Therefore, the replay logic also gets ignored. |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: HWS, Fix memory leak in hws_action_get_shared_stc_nic error flow
When an invalid stc_type is provided, the function allocates memory for
shared_stc but jumps to unlock_and_out without freeing it, causing a
memory leak.
Fix by jumping to free_shared_stc label instead to ensure proper cleanup. |
| 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:
iommufd/selftest: Catch overflow of uptr and length
syzkaller hits a WARN_ON when trying to have a uptr close to UINTPTR_MAX:
WARNING: CPU: 1 PID: 393 at drivers/iommu/iommufd/selftest.c:403 iommufd_test+0xb19/0x16f0
Modules linked in:
CPU: 1 PID: 393 Comm: repro Not tainted 6.2.0-c9c3395d5e3d #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:iommufd_test+0xb19/0x16f0
Code: 94 c4 31 ff 44 89 e6 e8 a5 54 17 ff 45 84 e4 0f 85 bb 0b 00 00 41 be fb ff ff ff e8 31 53 17 ff e9 a0 f7 ff ff e8 27 53 17 ff <0f> 0b 41 be 8
RSP: 0018:ffffc90000eabdc0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8214c487
RDX: 0000000000000000 RSI: ffff88800f5c8000 RDI: 0000000000000002
RBP: ffffc90000eabe48 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000000 R12: 00000000cd2b0000
R13: 00000000cd2af000 R14: 0000000000000000 R15: ffffc90000eabe68
FS: 00007f94d76d5740(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000043 CR3: 0000000006880006 CR4: 0000000000770ee0
PKRU: 55555554
Call Trace:
<TASK>
? write_comp_data+0x2f/0x90
iommufd_fops_ioctl+0x1ef/0x310
__x64_sys_ioctl+0x10e/0x160
? __pfx_iommufd_fops_ioctl+0x10/0x10
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
Check that the user memory range doesn't overflow. |
| 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. |
| This vulnerability affects Firefox < 143. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: target: iscsi: Fix a race condition between login_work and the login thread
In case a malicious initiator sends some random data immediately after a
login PDU; the iscsi_target_sk_data_ready() callback will schedule the
login_work and, at the same time, the negotiation may end without clearing
the LOGIN_FLAGS_INITIAL_PDU flag (because no additional PDU exchanges are
required to complete the login).
The login has been completed but the login_work function will find the
LOGIN_FLAGS_INITIAL_PDU flag set and will never stop from rescheduling
itself; at this point, if the initiator drops the connection, the
iscsit_conn structure will be freed, login_work will dereference a released
socket structure and the kernel crashes.
BUG: kernel NULL pointer dereference, address: 0000000000000230
PF: supervisor write access in kernel mode
PF: error_code(0x0002) - not-present page
Workqueue: events iscsi_target_do_login_rx [iscsi_target_mod]
RIP: 0010:_raw_read_lock_bh+0x15/0x30
Call trace:
iscsi_target_do_login_rx+0x75/0x3f0 [iscsi_target_mod]
process_one_work+0x1e8/0x3c0
Fix this bug by forcing login_work to stop after the login has been
completed and the socket callbacks have been restored.
Add a comment to clearify the return values of iscsi_target_do_login() |
| 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:
sctp: initialize more fields in sctp_v6_from_sk()
syzbot found that sin6_scope_id was not properly initialized,
leading to undefined behavior.
Clear sin6_scope_id and sin6_flowinfo.
BUG: KMSAN: uninit-value in __sctp_v6_cmp_addr+0x887/0x8c0 net/sctp/ipv6.c:649
__sctp_v6_cmp_addr+0x887/0x8c0 net/sctp/ipv6.c:649
sctp_inet6_cmp_addr+0x4f2/0x510 net/sctp/ipv6.c:983
sctp_bind_addr_conflict+0x22a/0x3b0 net/sctp/bind_addr.c:390
sctp_get_port_local+0x21eb/0x2440 net/sctp/socket.c:8452
sctp_get_port net/sctp/socket.c:8523 [inline]
sctp_listen_start net/sctp/socket.c:8567 [inline]
sctp_inet_listen+0x710/0xfd0 net/sctp/socket.c:8636
__sys_listen_socket net/socket.c:1912 [inline]
__sys_listen net/socket.c:1927 [inline]
__do_sys_listen net/socket.c:1932 [inline]
__se_sys_listen net/socket.c:1930 [inline]
__x64_sys_listen+0x343/0x4c0 net/socket.c:1930
x64_sys_call+0x271d/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:51
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Local variable addr.i.i created at:
sctp_get_port net/sctp/socket.c:8515 [inline]
sctp_listen_start net/sctp/socket.c:8567 [inline]
sctp_inet_listen+0x650/0xfd0 net/sctp/socket.c:8636
__sys_listen_socket net/socket.c:1912 [inline]
__sys_listen net/socket.c:1927 [inline]
__do_sys_listen net/socket.c:1932 [inline]
__se_sys_listen net/socket.c:1930 [inline]
__x64_sys_listen+0x343/0x4c0 net/socket.c:1930 |
| In the Linux kernel, the following vulnerability has been resolved:
powerpc: Don't try to copy PPR for task with NULL pt_regs
powerpc sets up PF_KTHREAD and PF_IO_WORKER with a NULL pt_regs, which
from my (arguably very short) checking is not commonly done for other
archs. This is fine, except when PF_IO_WORKER's have been created and
the task does something that causes a coredump to be generated. Then we
get this crash:
Kernel attempted to read user page (160) - exploit attempt? (uid: 1000)
BUG: Kernel NULL pointer dereference on read at 0x00000160
Faulting instruction address: 0xc0000000000c3a60
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=32 NUMA pSeries
Modules linked in: bochs drm_vram_helper drm_kms_helper xts binfmt_misc ecb ctr syscopyarea sysfillrect cbc sysimgblt drm_ttm_helper aes_generic ttm sg libaes evdev joydev virtio_balloon vmx_crypto gf128mul drm dm_mod fuse loop configfs drm_panel_orientation_quirks ip_tables x_tables autofs4 hid_generic usbhid hid xhci_pci xhci_hcd usbcore usb_common sd_mod
CPU: 1 PID: 1982 Comm: ppc-crash Not tainted 6.3.0-rc2+ #88
Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries
NIP: c0000000000c3a60 LR: c000000000039944 CTR: c0000000000398e0
REGS: c0000000041833b0 TRAP: 0300 Not tainted (6.3.0-rc2+)
MSR: 800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 88082828 XER: 200400f8
...
NIP memcpy_power7+0x200/0x7d0
LR ppr_get+0x64/0xb0
Call Trace:
ppr_get+0x40/0xb0 (unreliable)
__regset_get+0x180/0x1f0
regset_get_alloc+0x64/0x90
elf_core_dump+0xb98/0x1b60
do_coredump+0x1c34/0x24a0
get_signal+0x71c/0x1410
do_notify_resume+0x140/0x6f0
interrupt_exit_user_prepare_main+0x29c/0x320
interrupt_exit_user_prepare+0x6c/0xa0
interrupt_return_srr_user+0x8/0x138
Because ppr_get() is trying to copy from a PF_IO_WORKER with a NULL
pt_regs.
Check for a valid pt_regs in both ppc_get/ppr_set, and return an error
if not set. The actual error value doesn't seem to be important here, so
just pick -EINVAL.
[mpe: Trim oops in change log, add Fixes & Cc stable] |
| In the Linux kernel, the following vulnerability has been resolved:
bnxt_en: Fix memory corruption when FW resources change during ifdown
bnxt_set_dflt_rings() assumes that it is always called before any TC has
been created. So it doesn't take bp->num_tc into account and assumes
that it is always 0 or 1.
In the FW resource or capability change scenario, the FW will return
flags in bnxt_hwrm_if_change() that will cause the driver to
reinitialize and call bnxt_cancel_reservations(). This will lead to
bnxt_init_dflt_ring_mode() calling bnxt_set_dflt_rings() and bp->num_tc
may be greater than 1. This will cause bp->tx_ring[] to be sized too
small and cause memory corruption in bnxt_alloc_cp_rings().
Fix it by properly scaling the TX rings by bp->num_tc in the code
paths mentioned above. Add 2 helper functions to determine
bp->tx_nr_rings and bp->tx_nr_rings_per_tc. |
| In the Linux kernel, the following vulnerability has been resolved:
HID: hid-ntrig: fix unable to handle page fault in ntrig_report_version()
in ntrig_report_version(), hdev parameter passed from hid_probe().
sending descriptor to /dev/uhid can make hdev->dev.parent->parent to null
if hdev->dev.parent->parent is null, usb_dev has
invalid address(0xffffffffffffff58) that hid_to_usb_dev(hdev) returned
when usb_rcvctrlpipe() use usb_dev,it trigger
page fault error for address(0xffffffffffffff58)
add null check logic to ntrig_report_version()
before calling hid_to_usb_dev() |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: use array_index_nospec with indices that come from guest
min and dest_id are guest-controlled indices. Using array_index_nospec()
after the bounds checks clamps these values to mitigate speculative execution
side-channels. |
| In the Linux kernel, the following vulnerability has been resolved:
perf: Avoid undefined behavior from stopping/starting inactive events
Calling pmu->start()/stop() on perf events in PERF_EVENT_STATE_OFF can
leave event->hw.idx at -1. When PMU drivers later attempt to use this
negative index as a shift exponent in bitwise operations, it leads to UBSAN
shift-out-of-bounds reports.
The issue is a logical flaw in how event groups handle throttling when some
members are intentionally disabled. Based on the analysis and the
reproducer provided by Mark Rutland (this issue on both arm64 and x86-64).
The scenario unfolds as follows:
1. A group leader event is configured with a very aggressive sampling
period (e.g., sample_period = 1). This causes frequent interrupts and
triggers the throttling mechanism.
2. A child event in the same group is created in a disabled state
(.disabled = 1). This event remains in PERF_EVENT_STATE_OFF.
Since it hasn't been scheduled onto the PMU, its event->hw.idx remains
initialized at -1.
3. When throttling occurs, perf_event_throttle_group() and later
perf_event_unthrottle_group() iterate through all siblings, including
the disabled child event.
4. perf_event_throttle()/unthrottle() are called on this inactive child
event, which then call event->pmu->start()/stop().
5. The PMU driver receives the event with hw.idx == -1 and attempts to
use it as a shift exponent. e.g., in macros like PMCNTENSET(idx),
leading to the UBSAN report.
The throttling mechanism attempts to start/stop events that are not
actively scheduled on the hardware.
Move the state check into perf_event_throttle()/perf_event_unthrottle() so
that inactive events are skipped entirely. This ensures only active events
with a valid hw.idx are processed, preventing undefined behavior and
silencing UBSAN warnings. The corrected check ensures true before
proceeding with PMU operations.
The problem can be reproduced with the syzkaller reproducer: |
