linux-stable.git/drivers/char, branch v6.1.4

ipmi: fix use after free in _ipmi_destroy_user()

2023-01-07T10:11:52+00:00

commit a92ce570c81dc0feaeb12a429b4bc65686d17967 upstream.

The intf_free() function frees the "intf" pointer so we cannot
dereference it again on the next line.

Fixes: cbb79863fc31 ("ipmi: Don't allow device module unload when in use")
Signed-off-by: Dan Carpenter 
Message-Id: 
Cc:  # 5.5+
Signed-off-by: Corey Minyard 
Signed-off-by: Greg Kroah-Hartman

ipmi: fix long wait in unload when IPMI disconnect

2023-01-07T10:11:52+00:00

commit f6f1234d98cce69578bfac79df147a1f6660596c upstream.

When fixing the problem mentioned in PATCH1, we also found
the following problem:

If the IPMI is disconnected and in the sending process, the
uninstallation driver will be stuck for a long time.

The main problem is that uninstalling the driver waits for curr_msg to
be sent or HOSED. After stopping tasklet, the only place to trigger the
timeout mechanism is the circular poll in shutdown_smi.

The poll function delays 10us and calls smi_event_handler(smi_info,10).
Smi_event_handler deducts 10us from kcs->ibf_timeout.

But the poll func is followed by schedule_timeout_uninterruptible(1).
The time consumed here is not counted in kcs->ibf_timeout.

So when 10us is deducted from kcs->ibf_timeout, at least 1 jiffies has
actually passed. The waiting time has increased by more than a
hundredfold.

Now instead of calling poll(). call smi_event_handler() directly and
calculate the elapsed time.

For verification, you can directly use ebpf to check the kcs->
ibf_timeout for each call to kcs_event() when IPMI is disconnected.
Decrement at normal rate before unloading. The decrement rate becomes
very slow after unloading.

  $ bpftrace -e 'kprobe:kcs_event {printf("kcs->ibftimeout : %d\n",
      *(arg0+584));}'

Signed-off-by: Zhang Yuchen 
Message-Id: <20221007092617.87597-3-zhangyuchen.lcr@bytedance.com>
Signed-off-by: Corey Minyard 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

random: add helpers for random numbers with given floor or range

2023-01-07T10:11:40+00:00

commit 7f576b2593a978451416424e75f69ad1e3ae4efe upstream.

Now that we have get_random_u32_below(), it's nearly trivial to make
inline helpers to compute get_random_u32_above() and
get_random_u32_inclusive(), which will help clean up open coded loops
and manual computations throughout the tree.

One snag is that in order to make get_random_u32_inclusive() operate on
closed intervals, we have to do some (unlikely) special case handling if
get_random_u32_inclusive(0, U32_MAX) is called. The least expensive way
of doing this is actually to adjust the slowpath of
get_random_u32_below() to have its undefined 0 result just return the
output of get_random_u32(). We can make this basically free by calling
get_random_u32() before the branch, so that the branch latency gets
interleaved.

Cc: stable@vger.kernel.org # to ease future backports that use this api
Reviewed-by: Kees Cook 
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Greg Kroah-Hartman

random: use rejection sampling for uniform bounded random integers

2023-01-07T10:11:39+00:00

commit e9a688bcb19348862afe30d7c85bc37c4c293471 upstream.

Until the very recent commits, many bounded random integers were
calculated using `get_random_u32() % max_plus_one`, which not only
incurs the price of a division -- indicating performance mostly was not
a real issue -- but also does not result in a uniformly distributed
output if max_plus_one is not a power of two. Recent commits moved to
using `prandom_u32_max(max_plus_one)`, which replaces the division with
a faster multiplication, but still does not solve the issue with
non-uniform output.

For some users, maybe this isn't a problem, and for others, maybe it is,
but for the majority of users, probably the question has never been
posed and analyzed, and nobody thought much about it, probably assuming
random is random is random. In other words, the unthinking expectation
of most users is likely that the resultant numbers are uniform.

So we implement here an efficient way of generating uniform bounded
random integers. Through use of compile-time evaluation, and avoiding
divisions as much as possible, this commit introduces no measurable
overhead. At least for hot-path uses tested, any potential difference
was lost in the noise. On both clang and gcc, code generation is pretty
small.

The new function, get_random_u32_below(), lives in random.h, rather than
prandom.h, and has a "get_random_xxx" function name, because it is
suitable for all uses, including cryptography.

In order to be efficient, we implement a kernel-specific variant of
Daniel Lemire's algorithm from "Fast Random Integer Generation in an
Interval", linked below. The kernel's variant takes advantage of
constant folding to avoid divisions entirely in the vast majority of
cases, works on both 32-bit and 64-bit architectures, and requests a
minimal amount of bytes from the RNG.

Link: https://arxiv.org/pdf/1805.10941.pdf
Cc: stable@vger.kernel.org # to ease future backports that use this api
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Greg Kroah-Hartman

tpm: tpm_tis: Add the missed acpi_put_table() to fix memory leak

2023-01-04T10:29:02+00:00

commit db9622f762104459ff87ecdf885cc42c18053fd9 upstream.

In check_acpi_tpm2(), we get the TPM2 table just to make
sure the table is there, not used after the init, so the
acpi_put_table() should be added to release the ACPI memory.

Fixes: 4cb586a188d4 ("tpm_tis: Consolidate the platform and acpi probe flow")
Cc: stable@vger.kernel.org
Signed-off-by: Hanjun Guo 
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Greg Kroah-Hartman

tpm: tpm_crb: Add the missed acpi_put_table() to fix memory leak

2023-01-04T10:29:02+00:00

commit 37e90c374dd11cf4919c51e847c6d6ced0abc555 upstream.

In crb_acpi_add(), we get the TPM2 table to retrieve information
like start method, and then assign them to the priv data, so the
TPM2 table is not used after the init, should be freed, call
acpi_put_table() to fix the memory leak.

Fixes: 30fc8d138e91 ("tpm: TPM 2.0 CRB Interface")
Cc: stable@vger.kernel.org
Signed-off-by: Hanjun Guo 
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Greg Kroah-Hartman

tpm: acpi: Call acpi_put_table() to fix memory leak

2023-01-04T10:29:02+00:00

commit 8740a12ca2e2959531ad253bac99ada338b33d80 upstream.

The start and length of the event log area are obtained from
TPM2 or TCPA table, so we call acpi_get_table() to get the
ACPI information, but the acpi_get_table() should be coupled with
acpi_put_table() to release the ACPI memory, add the acpi_put_table()
properly to fix the memory leak.

While we are at it, remove the redundant empty line at the
end of the tpm_read_log_acpi().

Fixes: 0bfb23746052 ("tpm: Move eventlog files to a subdirectory")
Fixes: 85467f63a05c ("tpm: Add support for event log pointer found in TPM2 ACPI table")
Cc: stable@vger.kernel.org
Signed-off-by: Hanjun Guo 
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Greg Kroah-Hartman

ipmi: fix memleak when unload ipmi driver

2022-12-31T12:32:59+00:00

[ Upstream commit 36992eb6b9b83f7f9cdc8e74fb5799d7b52e83e9 ]

After the IPMI disconnect problem, the memory kept rising and we tried
to unload the driver to free the memory. However, only part of the
free memory is recovered after the driver is uninstalled. Using
ebpf to hook free functions, we find that neither ipmi_user nor
ipmi_smi_msg is free, only ipmi_recv_msg is free.

We find that the deliver_smi_err_response call in clean_smi_msgs does
the destroy processing on each message from the xmit_msg queue without
checking the return value and free ipmi_smi_msg.

deliver_smi_err_response is called only at this location. Adding the
free handling has no effect.

To verify, try using ebpf to trace the free function.

  $ bpftrace -e 'kretprobe:ipmi_alloc_recv_msg {printf("alloc rcv
      %p\n",retval);} kprobe:free_recv_msg {printf("free recv %p\n",
      arg0)} kretprobe:ipmi_alloc_smi_msg {printf("alloc smi %p\n",
        retval);} kprobe:free_smi_msg {printf("free smi  %p\n",arg0)}'

Signed-off-by: Zhang Yuchen 
Message-Id: <20221007092617.87597-4-zhangyuchen.lcr@bytedance.com>
[Fixed the comment above handle_one_recv_msg().]
Signed-off-by: Corey Minyard 
Signed-off-by: Sasha Levin

hwrng: geode - Fix PCI device refcount leak

2022-12-31T12:32:37+00:00

[ Upstream commit 9f6ec8dc574efb7f4f3d7ee9cd59ae307e78f445 ]

for_each_pci_dev() is implemented by pci_get_device(). The comment of
pci_get_device() says that it will increase the reference count for the
returned pci_dev and also decrease the reference count for the input
pci_dev @from if it is not NULL.

If we break for_each_pci_dev() loop with pdev not NULL, we need to call
pci_dev_put() to decrease the reference count. We add a new struct
'amd_geode_priv' to record pointer of the pci_dev and membase, and then
add missing pci_dev_put() for the normal and error path.

Fixes: ef5d862734b8 ("[PATCH] Add Geode HW RNG driver")
Signed-off-by: Xiongfeng Wang 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin

hwrng: amd - Fix PCI device refcount leak

2022-12-31T12:32:37+00:00

[ Upstream commit ecadb5b0111ea19fc7c240bb25d424a94471eb7d ]

for_each_pci_dev() is implemented by pci_get_device(). The comment of
pci_get_device() says that it will increase the reference count for the
returned pci_dev and also decrease the reference count for the input
pci_dev @from if it is not NULL.

If we break for_each_pci_dev() loop with pdev not NULL, we need to call
pci_dev_put() to decrease the reference count. Add the missing
pci_dev_put() for the normal and error path.

Fixes: 96d63c0297cc ("[PATCH] Add AMD HW RNG driver")
Signed-off-by: Xiongfeng Wang 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin