| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
net: core: remove unnecessary frame_sz check in bpf_xdp_adjust_tail()
Syzkaller reported the following issue:
=======================================
Too BIG xdp->frame_sz = 131072
WARNING: CPU: 0 PID: 5020 at net/core/filter.c:4121
____bpf_xdp_adjust_tail net/core/filter.c:4121 [inline]
WARNING: CPU: 0 PID: 5020 at net/core/filter.c:4121
bpf_xdp_adjust_tail+0x466/0xa10 net/core/filter.c:4103
...
Call Trace:
<TASK>
bpf_prog_4add87e5301a4105+0x1a/0x1c
__bpf_prog_run include/linux/filter.h:600 [inline]
bpf_prog_run_xdp include/linux/filter.h:775 [inline]
bpf_prog_run_generic_xdp+0x57e/0x11e0 net/core/dev.c:4721
netif_receive_generic_xdp net/core/dev.c:4807 [inline]
do_xdp_generic+0x35c/0x770 net/core/dev.c:4866
tun_get_user+0x2340/0x3ca0 drivers/net/tun.c:1919
tun_chr_write_iter+0xe8/0x210 drivers/net/tun.c:2043
call_write_iter include/linux/fs.h:1871 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x650/0xe40 fs/read_write.c:584
ksys_write+0x12f/0x250 fs/read_write.c:637
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
xdp->frame_sz > PAGE_SIZE check was introduced in commit c8741e2bfe87
("xdp: Allow bpf_xdp_adjust_tail() to grow packet size"). But Jesper
Dangaard Brouer <jbrouer@redhat.com> noted that after introducing the
xdp_init_buff() which all XDP driver use - it's safe to remove this
check. The original intend was to catch cases where XDP drivers have
not been updated to use xdp.frame_sz, but that is not longer a concern
(since xdp_init_buff).
Running the initial syzkaller repro it was discovered that the
contiguous physical memory allocation is used for both xdp paths in
tun_get_user(), e.g. tun_build_skb() and tun_alloc_skb(). It was also
stated by Jesper Dangaard Brouer <jbrouer@redhat.com> that XDP can
work on higher order pages, as long as this is contiguous physical
memory (e.g. a page). |
| In the Linux kernel, the following vulnerability has been resolved:
powerpc/rtas: avoid device tree lookups in rtas_os_term()
rtas_os_term() is called during panic. Its behavior depends on a couple
of conditions in the /rtas node of the device tree, the traversal of
which entails locking and local IRQ state changes. If the kernel panics
while devtree_lock is held, rtas_os_term() as currently written could
hang.
Instead of discovering the relevant characteristics at panic time,
cache them in file-static variables at boot. Note the lookup for
"ibm,extended-os-term" is converted to of_property_read_bool() since it
is a boolean property, not an RTAS function token.
[mpe: Incorporate suggested change from Nick] |
| In the Linux kernel, the following vulnerability has been resolved:
erofs: fix missing unmap if z_erofs_get_extent_compressedlen() fails
Otherwise, meta buffers could be leaked. |
| In the Linux kernel, the following vulnerability has been resolved:
bus: fsl-mc: Check return value of platform_get_resource()
platform_get_resource() returns NULL in case of failure, so check its
return value and propagate the error in order to prevent NULL pointer
dereference. |
| In the Linux kernel, the following vulnerability has been resolved:
security: Restrict CONFIG_ZERO_CALL_USED_REGS to gcc or clang > 15.0.6
A bad bug in clang's implementation of -fzero-call-used-regs can result
in NULL pointer dereferences (see the links above the check for more
information). Restrict CONFIG_CC_HAS_ZERO_CALL_USED_REGS to either a
supported GCC version or a clang newer than 15.0.6, which will catch
both a theoretical 15.0.7 and the upcoming 16.0.0, which will both have
the bug fixed. |
| In the Linux kernel, the following vulnerability has been resolved:
vfio/type1: fix cap_migration information leak
Fix an information leak where an uninitialized hole in struct
vfio_iommu_type1_info_cap_migration on the stack is exposed to userspace.
The definition of struct vfio_iommu_type1_info_cap_migration contains a hole as
shown in this pahole(1) output:
struct vfio_iommu_type1_info_cap_migration {
struct vfio_info_cap_header header; /* 0 8 */
__u32 flags; /* 8 4 */
/* XXX 4 bytes hole, try to pack */
__u64 pgsize_bitmap; /* 16 8 */
__u64 max_dirty_bitmap_size; /* 24 8 */
/* size: 32, cachelines: 1, members: 4 */
/* sum members: 28, holes: 1, sum holes: 4 */
/* last cacheline: 32 bytes */
};
The cap_mig variable is filled in without initializing the hole:
static int vfio_iommu_migration_build_caps(struct vfio_iommu *iommu,
struct vfio_info_cap *caps)
{
struct vfio_iommu_type1_info_cap_migration cap_mig;
cap_mig.header.id = VFIO_IOMMU_TYPE1_INFO_CAP_MIGRATION;
cap_mig.header.version = 1;
cap_mig.flags = 0;
/* support minimum pgsize */
cap_mig.pgsize_bitmap = (size_t)1 << __ffs(iommu->pgsize_bitmap);
cap_mig.max_dirty_bitmap_size = DIRTY_BITMAP_SIZE_MAX;
return vfio_info_add_capability(caps, &cap_mig.header, sizeof(cap_mig));
}
The structure is then copied to a temporary location on the heap. At this point
it's already too late and ioctl(VFIO_IOMMU_GET_INFO) copies it to userspace
later:
int vfio_info_add_capability(struct vfio_info_cap *caps,
struct vfio_info_cap_header *cap, size_t size)
{
struct vfio_info_cap_header *header;
header = vfio_info_cap_add(caps, size, cap->id, cap->version);
if (IS_ERR(header))
return PTR_ERR(header);
memcpy(header + 1, cap + 1, size - sizeof(*header));
return 0;
}
This issue was found by code inspection. |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: safexcel - Cleanup ring IRQ workqueues on load failure
A failure loading the safexcel driver results in the following warning
on boot, because the IRQ affinity has not been correctly cleaned up.
Ensure we clean up the affinity and workqueues on a failure to load the
driver.
crypto-safexcel: probe of f2800000.crypto failed with error -2
------------[ cut here ]------------
WARNING: CPU: 1 PID: 232 at kernel/irq/manage.c:1913 free_irq+0x300/0x340
Modules linked in: hwmon mdio_i2c crypto_safexcel(+) md5 sha256_generic libsha256 authenc libdes omap_rng rng_core nft_masq nft_nat nft_chain_nat nf_nat nft_ct nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables libcrc32c nfnetlink fuse autofs4
CPU: 1 PID: 232 Comm: systemd-udevd Tainted: G W 6.1.6-00002-g9d4898824677 #3
Hardware name: MikroTik RB5009 (DT)
pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : free_irq+0x300/0x340
lr : free_irq+0x2e0/0x340
sp : ffff800008fa3890
x29: ffff800008fa3890 x28: 0000000000000000 x27: 0000000000000000
x26: ffff8000008e6dc0 x25: ffff000009034cac x24: ffff000009034d50
x23: 0000000000000000 x22: 000000000000004a x21: ffff0000093e0d80
x20: ffff000009034c00 x19: ffff00000615fc00 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 000075f5c1584c5e
x14: 0000000000000017 x13: 0000000000000000 x12: 0000000000000040
x11: ffff000000579b60 x10: ffff000000579b62 x9 : ffff800008bbe370
x8 : ffff000000579dd0 x7 : 0000000000000000 x6 : ffff000000579e18
x5 : ffff000000579da8 x4 : ffff800008ca0000 x3 : ffff800008ca0188
x2 : 0000000013033204 x1 : ffff000009034c00 x0 : ffff8000087eadf0
Call trace:
free_irq+0x300/0x340
devm_irq_release+0x14/0x20
devres_release_all+0xa0/0x100
device_unbind_cleanup+0x14/0x60
really_probe+0x198/0x2d4
__driver_probe_device+0x74/0xdc
driver_probe_device+0x3c/0x110
__driver_attach+0x8c/0x190
bus_for_each_dev+0x6c/0xc0
driver_attach+0x20/0x30
bus_add_driver+0x148/0x1fc
driver_register+0x74/0x120
__platform_driver_register+0x24/0x30
safexcel_init+0x48/0x1000 [crypto_safexcel]
do_one_initcall+0x4c/0x1b0
do_init_module+0x44/0x1cc
load_module+0x1724/0x1be4
__do_sys_finit_module+0xbc/0x110
__arm64_sys_finit_module+0x1c/0x24
invoke_syscall+0x44/0x110
el0_svc_common.constprop.0+0xc0/0xe0
do_el0_svc+0x20/0x80
el0_svc+0x14/0x4c
el0t_64_sync_handler+0xb0/0xb4
el0t_64_sync+0x148/0x14c
---[ end trace 0000000000000000 ]--- |
| In the Linux kernel, the following vulnerability has been resolved:
mmc: alcor: 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. |
| In the Linux kernel, the following vulnerability has been resolved:
remoteproc: pru: Fix potential NULL pointer dereference in pru_rproc_set_ctable()
pru_rproc_set_ctable() accessed rproc->priv before the IS_ERR_OR_NULL
check, which could lead to a null pointer dereference. Move the pru
assignment, ensuring we never dereference a NULL rproc pointer. |
| In the Linux kernel, the following vulnerability has been resolved:
rapidio: rio: fix possible name leak in rio_register_mport()
If device_register() returns error, the name allocated by dev_set_name()
need be freed. It should use put_device() to give up the reference in the
error path, so that the name can be freed in kobject_cleanup(), and
list_del() is called to delete the port from rio_mports. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: prevent leak of lsm program after failed attach
In [0], we added the ability to bpf_prog_attach LSM programs to cgroups,
but in our validation to make sure the prog is meant to be attached to
BPF_LSM_CGROUP, we return too early if the check fails. This results in
lack of decrementing prog's refcnt (through bpf_prog_put)
leaving the LSM program alive past the point of the expected lifecycle.
This fix allows for the decrement to take place.
[0] https://lore.kernel.org/all/20220628174314.1216643-4-sdf@google.com/ |
| In the Linux kernel, the following vulnerability has been resolved:
s390/dcssblk: fix kernel crash with list_add corruption
Commit fb08a1908cb1 ("dax: simplify the dax_device <-> gendisk
association") introduced new logic for gendisk association, requiring
drivers to explicitly call dax_add_host() and dax_remove_host().
For dcssblk driver, some dax_remove_host() calls were missing, e.g. in
device remove path. The commit also broke error handling for out_dax case
in device add path, resulting in an extra put_device() w/o the previous
get_device() in that case.
This lead to stale xarray entries after device add / remove cycles. In the
case when a previously used struct gendisk pointer (xarray index) would be
used again, because blk_alloc_disk() happened to return such a pointer, the
xa_insert() in dax_add_host() would fail and go to out_dax, doing the extra
put_device() in the error path. In combination with an already flawed error
handling in dcssblk (device_register() cleanup), which needs to be
addressed in a separate patch, this resulted in a missing device_del() /
klist_del(), and eventually in the kernel crash with list_add corruption on
a subsequent device_add() / klist_add().
Fix this by adding the missing dax_remove_host() calls, and also move the
put_device() in the error path to restore the previous logic. |
| In the Linux kernel, the following vulnerability has been resolved:
pcmcia: rsrc_nonstatic: Fix memory leak in nonstatic_release_resource_db()
When nonstatic_release_resource_db() frees all resources associated
with an PCMCIA socket, it forgets to free socket_data too, causing
a memory leak observable with kmemleak:
unreferenced object 0xc28d1000 (size 64):
comm "systemd-udevd", pid 297, jiffies 4294898478 (age 194.484s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 f0 85 0e c3 00 00 00 00 ................
00 00 00 00 0c 10 8d c2 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffda4245>] __kmem_cache_alloc_node+0x2d7/0x4a0
[<7e51f0c8>] kmalloc_trace+0x31/0xa4
[<d52b4ca0>] nonstatic_init+0x24/0x1a4 [pcmcia_rsrc]
[<a2f13e08>] pcmcia_register_socket+0x200/0x35c [pcmcia_core]
[<a728be1b>] yenta_probe+0x4d8/0xa70 [yenta_socket]
[<c48fac39>] pci_device_probe+0x99/0x194
[<84b7c690>] really_probe+0x181/0x45c
[<8060fe6e>] __driver_probe_device+0x75/0x1f4
[<b9b76f43>] driver_probe_device+0x28/0xac
[<648b766f>] __driver_attach+0xeb/0x1e4
[<6e9659eb>] bus_for_each_dev+0x61/0xb4
[<25a669f3>] driver_attach+0x1e/0x28
[<d8671d6b>] bus_add_driver+0x102/0x20c
[<df0d323c>] driver_register+0x5b/0x120
[<942cd8a4>] __pci_register_driver+0x44/0x4c
[<e536027e>] __UNIQUE_ID___addressable_cleanup_module188+0x1c/0xfffff000 [iTCO_vendor_support]
Fix this by freeing socket_data too.
Tested on a Acer Travelmate 4002WLMi by manually binding/unbinding
the yenta_cardbus driver (yenta_socket). |
| In the Linux kernel, the following vulnerability has been resolved:
vhost_vdpa: fix the crash in unmap a large memory
While testing in vIOMMU, sometimes Guest will unmap very large memory,
which will cause the crash. To fix this, add a new function
vhost_vdpa_general_unmap(). This function will only unmap the memory
that saved in iotlb.
Call Trace:
[ 647.820144] ------------[ cut here ]------------
[ 647.820848] kernel BUG at drivers/iommu/intel/iommu.c:1174!
[ 647.821486] invalid opcode: 0000 [#1] PREEMPT SMP PTI
[ 647.822082] CPU: 10 PID: 1181 Comm: qemu-system-x86 Not tainted 6.0.0-rc1home_lulu_2452_lulu7_vhost+ #62
[ 647.823139] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-29-g6a62e0cb0dfe-prebuilt.qem4
[ 647.824365] RIP: 0010:domain_unmap+0x48/0x110
[ 647.825424] Code: 48 89 fb 8d 4c f6 1e 39 c1 0f 4f c8 83 e9 0c 83 f9 3f 7f 18 48 89 e8 48 d3 e8 48 85 c0 75 59
[ 647.828064] RSP: 0018:ffffae5340c0bbf0 EFLAGS: 00010202
[ 647.828973] RAX: 0000000000000001 RBX: ffff921793d10540 RCX: 000000000000001b
[ 647.830083] RDX: 00000000080000ff RSI: 0000000000000001 RDI: ffff921793d10540
[ 647.831214] RBP: 0000000007fc0100 R08: ffffae5340c0bcd0 R09: 0000000000000003
[ 647.832388] R10: 0000007fc0100000 R11: 0000000000100000 R12: 00000000080000ff
[ 647.833668] R13: ffffae5340c0bcd0 R14: ffff921793d10590 R15: 0000008000100000
[ 647.834782] FS: 00007f772ec90640(0000) GS:ffff921ce7a80000(0000) knlGS:0000000000000000
[ 647.836004] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 647.836990] CR2: 00007f02c27a3a20 CR3: 0000000101b0c006 CR4: 0000000000372ee0
[ 647.838107] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 647.839283] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 647.840666] Call Trace:
[ 647.841437] <TASK>
[ 647.842107] intel_iommu_unmap_pages+0x93/0x140
[ 647.843112] __iommu_unmap+0x91/0x1b0
[ 647.844003] iommu_unmap+0x6a/0x95
[ 647.844885] vhost_vdpa_unmap+0x1de/0x1f0 [vhost_vdpa]
[ 647.845985] vhost_vdpa_process_iotlb_msg+0xf0/0x90b [vhost_vdpa]
[ 647.847235] ? _raw_spin_unlock+0x15/0x30
[ 647.848181] ? _copy_from_iter+0x8c/0x580
[ 647.849137] vhost_chr_write_iter+0xb3/0x430 [vhost]
[ 647.850126] vfs_write+0x1e4/0x3a0
[ 647.850897] ksys_write+0x53/0xd0
[ 647.851688] do_syscall_64+0x3a/0x90
[ 647.852508] entry_SYSCALL_64_after_hwframe+0x63/0xcd
[ 647.853457] RIP: 0033:0x7f7734ef9f4f
[ 647.854408] Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 29 76 f8 ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c8
[ 647.857217] RSP: 002b:00007f772ec8f040 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
[ 647.858486] RAX: ffffffffffffffda RBX: 00000000fef00000 RCX: 00007f7734ef9f4f
[ 647.859713] RDX: 0000000000000048 RSI: 00007f772ec8f090 RDI: 0000000000000010
[ 647.860942] RBP: 00007f772ec8f1a0 R08: 0000000000000000 R09: 0000000000000000
[ 647.862206] R10: 0000000000000001 R11: 0000000000000293 R12: 0000000000000010
[ 647.863446] R13: 0000000000000002 R14: 0000000000000000 R15: ffffffff01100000
[ 647.864692] </TASK>
[ 647.865458] Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs v]
[ 647.874688] ---[ end trace 0000000000000000 ]--- |
| In the Linux kernel, the following vulnerability has been resolved:
drm/bridge: it6505: Initialize AUX channel in it6505_i2c_probe
During device boot, the HPD interrupt could be triggered before the DRM
subsystem registers it6505 as a DRM bridge. In such cases, the driver
tries to access AUX channel and causes NULL pointer dereference.
Initializing the AUX channel earlier to prevent such error. |
| In the Linux kernel, the following vulnerability has been resolved:
net: nsh: Use correct mac_offset to unwind gso skb in nsh_gso_segment()
As the call trace shows, skb_panic was caused by wrong skb->mac_header
in nsh_gso_segment():
invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 3 PID: 2737 Comm: syz Not tainted 6.3.0-next-20230505 #1
RIP: 0010:skb_panic+0xda/0xe0
call Trace:
skb_push+0x91/0xa0
nsh_gso_segment+0x4f3/0x570
skb_mac_gso_segment+0x19e/0x270
__skb_gso_segment+0x1e8/0x3c0
validate_xmit_skb+0x452/0x890
validate_xmit_skb_list+0x99/0xd0
sch_direct_xmit+0x294/0x7c0
__dev_queue_xmit+0x16f0/0x1d70
packet_xmit+0x185/0x210
packet_snd+0xc15/0x1170
packet_sendmsg+0x7b/0xa0
sock_sendmsg+0x14f/0x160
The root cause is:
nsh_gso_segment() use skb->network_header - nhoff to reset mac_header
in skb_gso_error_unwind() if inner-layer protocol gso fails.
However, skb->network_header may be reset by inner-layer protocol
gso function e.g. mpls_gso_segment. skb->mac_header reset by the
inaccurate network_header will be larger than skb headroom.
nsh_gso_segment
nhoff = skb->network_header - skb->mac_header;
__skb_pull(skb,nsh_len)
skb_mac_gso_segment
mpls_gso_segment
skb_reset_network_header(skb);//skb->network_header+=nsh_len
return -EINVAL;
skb_gso_error_unwind
skb_push(skb, nsh_len);
skb->mac_header = skb->network_header - nhoff;
// skb->mac_header > skb->headroom, cause skb_push panic
Use correct mac_offset to restore mac_header and get rid of nhoff. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: snic: Fix possible UAF in snic_tgt_create()
Smatch reports a warning as follows:
drivers/scsi/snic/snic_disc.c:307 snic_tgt_create() warn:
'&tgt->list' not removed from list
If device_add() fails in snic_tgt_create(), tgt will be freed, but
tgt->list will not be removed from snic->disc.tgt_list, then list traversal
may cause UAF.
Remove from snic->disc.tgt_list before free(). |
| In the Linux kernel, the following vulnerability has been resolved:
tracing: Fix WARN_ON in tracing_buffers_mmap_close for split VMAs
When a VMA is split (e.g., by partial munmap or MAP_FIXED), the kernel
calls vm_ops->close on each portion. For trace buffer mappings, this
results in ring_buffer_unmap() being called multiple times while
ring_buffer_map() was only called once.
This causes ring_buffer_unmap() to return -ENODEV on subsequent calls
because user_mapped is already 0, triggering a WARN_ON.
Trace buffer mappings cannot support partial mappings because the ring
buffer structure requires the complete buffer including the meta page.
Fix this by adding a may_split callback that returns -EINVAL to prevent
VMA splits entirely. |
| In the Linux kernel, the following vulnerability has been resolved:
kcm: Fix memory leak in error path of kcm_sendmsg()
syzbot reported a memory leak like below:
BUG: memory leak
unreferenced object 0xffff88810b088c00 (size 240):
comm "syz-executor186", pid 5012, jiffies 4294943306 (age 13.680s)
hex dump (first 32 bytes):
00 89 08 0b 81 88 ff ff 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff83e5d5ff>] __alloc_skb+0x1ef/0x230 net/core/skbuff.c:634
[<ffffffff84606e59>] alloc_skb include/linux/skbuff.h:1289 [inline]
[<ffffffff84606e59>] kcm_sendmsg+0x269/0x1050 net/kcm/kcmsock.c:815
[<ffffffff83e479c6>] sock_sendmsg_nosec net/socket.c:725 [inline]
[<ffffffff83e479c6>] sock_sendmsg+0x56/0xb0 net/socket.c:748
[<ffffffff83e47f55>] ____sys_sendmsg+0x365/0x470 net/socket.c:2494
[<ffffffff83e4c389>] ___sys_sendmsg+0xc9/0x130 net/socket.c:2548
[<ffffffff83e4c536>] __sys_sendmsg+0xa6/0x120 net/socket.c:2577
[<ffffffff84ad7bb8>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<ffffffff84ad7bb8>] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
[<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
In kcm_sendmsg(), kcm_tx_msg(head)->last_skb is used as a cursor to append
newly allocated skbs to 'head'. If some bytes are copied, an error occurred,
and jumped to out_error label, 'last_skb' is left unmodified. A later
kcm_sendmsg() will use an obsoleted 'last_skb' reference, corrupting the
'head' frag_list and causing the leak.
This patch fixes this issue by properly updating the last allocated skb in
'last_skb'. |
| In the Linux kernel, the following vulnerability has been resolved:
fs: Protect reconfiguration of sb read-write from racing writes
The reconfigure / remount code takes a lot of effort to protect
filesystem's reconfiguration code from racing writes on remounting
read-only. However during remounting read-only filesystem to read-write
mode userspace writes can start immediately once we clear SB_RDONLY
flag. This is inconvenient for example for ext4 because we need to do
some writes to the filesystem (such as preparation of quota files)
before we can take userspace writes so we are clearing SB_RDONLY flag
before we are fully ready to accept userpace writes and syzbot has found
a way to exploit this [1]. Also as far as I'm reading the code
the filesystem remount code was protected from racing writes in the
legacy mount path by the mount's MNT_READONLY flag so this is relatively
new problem. It is actually fairly easy to protect remount read-write
from racing writes using sb->s_readonly_remount flag so let's just do
that instead of having to workaround these races in the filesystem code.
[1] https://lore.kernel.org/all/00000000000006a0df05f6667499@google.com/T/ |
