From: Ammar Faizi <[email protected]>
To: Borislav Petkov <[email protected]>, Thomas Gleixner <[email protected]>
Cc: Ammar Faizi <[email protected]>,
Alviro Iskandar Setiawan <[email protected]>,
Dave Hansen <[email protected]>,
"H. Peter Anvin" <[email protected]>, Ingo Molnar <[email protected]>,
Tony Luck <[email protected]>,
Yazen Ghannam <[email protected]>,
Linux Edac Mailing List <[email protected]>,
Linux Kernel Mailing List <[email protected]>,
Stable Kernel <[email protected]>,
GNU/Weeb Mailing List <[email protected]>,
x86 Mailing List <[email protected]>
Subject: [PATCH v6 2/2] x86/MCE/AMD: Fix memory leak when `threshold_create_bank()` fails
Date: Tue, 29 Mar 2022 17:47:05 +0700 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
In mce_threshold_create_device(), if threshold_create_bank() fails, the
@bp will be leaked, because the call to mce_threshold_remove_device()
will not free the @bp. mce_threshold_remove_device() frees
@threshold_banks. At that point, the @bp has not been written to
@threshold_banks, @threshold_banks is NULL, so the call is just a nop.
Fix this by extracting the cleanup part into a new static function
__threshold_remove_device(), then call it from create/remove device
functions.
Also, eliminate the "goto out_err", just early return inside the loop
if the creation fails.
Cc: [email protected] # v5.8+
Fixes: 6458de97fc15 ("x86/mce/amd: Straighten CPU hotplug path")
Co-developed-by: Alviro Iskandar Setiawan <[email protected]>
Signed-off-by: Alviro Iskandar Setiawan <[email protected]>
Co-developed-by: Yazen Ghannam <[email protected]>
Signed-off-by: Yazen Ghannam <[email protected]>
Signed-off-by: Ammar Faizi <[email protected]>
---
v6:
- Change the helper function name to __threshold_remove_device().
---
arch/x86/kernel/cpu/mce/amd.c | 32 +++++++++++++++++++-------------
1 file changed, 19 insertions(+), 13 deletions(-)
diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
index 1940d305db1c..d293ae088d6b 100644
--- a/arch/x86/kernel/cpu/mce/amd.c
+++ b/arch/x86/kernel/cpu/mce/amd.c
@@ -1294,10 +1294,23 @@ static void threshold_remove_bank(struct threshold_bank *bank)
kfree(bank);
}
+static void __threshold_remove_device(struct threshold_bank **bp,
+ unsigned int numbanks)
+{
+ unsigned int bank;
+
+ for (bank = 0; bank < numbanks; bank++) {
+ if (bp[bank]) {
+ threshold_remove_bank(bp[bank]);
+ bp[bank] = NULL;
+ }
+ }
+ kfree(bp);
+}
+
int mce_threshold_remove_device(unsigned int cpu)
{
struct threshold_bank **bp = this_cpu_read(threshold_banks);
- unsigned int bank, numbanks = this_cpu_read(mce_num_banks);
if (!bp)
return 0;
@@ -1308,13 +1321,7 @@ int mce_threshold_remove_device(unsigned int cpu)
*/
this_cpu_write(threshold_banks, NULL);
- for (bank = 0; bank < numbanks; bank++) {
- if (bp[bank]) {
- threshold_remove_bank(bp[bank]);
- bp[bank] = NULL;
- }
- }
- kfree(bp);
+ __threshold_remove_device(bp, this_cpu_read(mce_num_banks));
return 0;
}
@@ -1351,15 +1358,14 @@ int mce_threshold_create_device(unsigned int cpu)
if (!(this_cpu_read(bank_map) & (1 << bank)))
continue;
err = threshold_create_bank(bp, cpu, bank);
- if (err)
- goto out_err;
+ if (err) {
+ __threshold_remove_device(bp, numbanks);
+ return err;
+ }
}
this_cpu_write(threshold_banks, bp);
if (thresholding_irq_en)
mce_threshold_vector = amd_threshold_interrupt;
return 0;
-out_err:
- mce_threshold_remove_device(cpu);
- return err;
}
--
Ammar Faizi
next prev parent reply other threads:[~2022-03-29 10:47 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-29 10:47 [PATCH v6 0/2] Two x86 fixes Ammar Faizi
2022-03-29 10:47 ` [PATCH v6 1/2] x86/delay: Fix the wrong asm constraint in `delay_loop()` Ammar Faizi
2022-04-01 17:42 ` Dave Hansen
2022-04-02 5:15 ` Ammar Faizi
2022-04-03 16:57 ` Thomas Gleixner
2022-04-03 17:11 ` Ammar Faizi
2022-04-03 17:14 ` Thomas Gleixner
2022-04-05 20:50 ` [tip: x86/misc] x86/delay: Fix the wrong asm constraint in delay_loop() tip-bot2 for Ammar Faizi
2022-03-29 10:47 ` Ammar Faizi [this message]
2022-04-03 17:03 ` [PATCH v6 2/2] x86/MCE/AMD: Fix memory leak when `threshold_create_bank()` fails Thomas Gleixner
2022-04-03 17:43 ` Ammar Faizi
2022-04-03 17:45 ` Ammar Faizi
2022-04-03 18:46 ` Borislav Petkov
2022-04-05 20:56 ` [tip: ras/core] x86/MCE/AMD: Fix memory leak when threshold_create_bank() fails tip-bot2 for Ammar Faizi
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