The following commit has been merged into the ras/core branch of tip:
Commit-ID: e5f28623ceb103e13fc3d7bd45edf9818b227fd0 Gitweb: https://git.kernel.org/tip/e5f28623ceb103e13fc3d7bd45edf9818b227fd0 Author: Ammar Faizi ammarfaizi2@gnuweeb.org AuthorDate: Tue, 29 Mar 2022 17:47:05 +07:00 Committer: Borislav Petkov bp@suse.de CommitterDate: Tue, 05 Apr 2022 21:24:37 +02:00
x86/MCE/AMD: Fix memory leak when threshold_create_bank() fails
In mce_threshold_create_device(), if threshold_create_bank() fails, the previously allocated threshold banks array @bp will be leaked because the call to mce_threshold_remove_device() will not free it.
This happens because mce_threshold_remove_device() fetches the pointer through the threshold_banks per-CPU variable but bp is written there only after the bank creation is successful, and not before, when threshold_create_bank() fails.
Add a helper which unwinds all the bank creation work previously done and pass into it the previously allocated threshold banks array for freeing.
[ bp: Massage. ]
Fixes: 6458de97fc15 ("x86/mce/amd: Straighten CPU hotplug path") Co-developed-by: Alviro Iskandar Setiawan alviro.iskandar@gnuweeb.org Signed-off-by: Alviro Iskandar Setiawan alviro.iskandar@gnuweeb.org Co-developed-by: Yazen Ghannam yazen.ghannam@amd.com Signed-off-by: Yazen Ghannam yazen.ghannam@amd.com Signed-off-by: Ammar Faizi ammarfaizi2@gnuweeb.org Signed-off-by: Borislav Petkov bp@suse.de Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220329104705.65256-3-ammarfaizi2@gnuweeb.org --- 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 1940d30..1c87501 100644 --- a/arch/x86/kernel/cpu/mce/amd.c +++ b/arch/x86/kernel/cpu/mce/amd.c @@ -1294,10 +1294,23 @@ out_free: kfree(bank); }
+static void __threshold_remove_device(struct threshold_bank **bp) +{ + unsigned int bank, numbanks = this_cpu_read(mce_num_banks); + + for (bank = 0; bank < numbanks; bank++) { + if (!bp[bank]) + continue; + + 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); 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); + 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; }