From: Michael Ellerman mpe@ellerman.id.au
commit 93900337b9ac2f4eca427eff6d187be2dc3b5551 upstream.
create_cpu_loop() calls smu_sat_get_sdb_partition() which does kmalloc() and returns the allocated buffer. In fact it's called twice, and neither buffer is freed.
This results in a memory leak as reported by Erhard: unreferenced object 0xc00000047081f840 (size 32): comm "kwindfarm", pid 203, jiffies 4294880630 (age 5552.877s) hex dump (first 32 bytes): c8 06 02 7f ff 02 ff 01 fb bf 00 41 00 20 00 00 ...........A. .. 00 07 89 37 00 a0 00 00 00 00 00 00 00 00 00 00 ...7............ backtrace: [<0000000083f0a65c>] .smu_sat_get_sdb_partition+0xc4/0x2d0 [windfarm_smu_sat] [<000000003010fcb7>] .pm112_wf_notify+0x104c/0x13bc [windfarm_pm112] [<00000000b958b2dd>] .notifier_call_chain+0xa8/0x180 [<0000000070490868>] .blocking_notifier_call_chain+0x64/0x90 [<00000000131d8149>] .wf_thread_func+0x114/0x1a0 [<000000000d54838d>] .kthread+0x13c/0x190 [<00000000669b72bc>] .ret_from_kernel_thread+0x58/0x64 unreferenced object 0xc0000004737089f0 (size 16): comm "kwindfarm", pid 203, jiffies 4294880879 (age 5552.050s) hex dump (first 16 bytes): c4 04 01 7f 22 11 e0 e6 ff 55 7b 12 ec 11 00 00 ...."....U{..... backtrace: [<0000000083f0a65c>] .smu_sat_get_sdb_partition+0xc4/0x2d0 [windfarm_smu_sat] [<00000000b94ef7e1>] .pm112_wf_notify+0x1294/0x13bc [windfarm_pm112] [<00000000b958b2dd>] .notifier_call_chain+0xa8/0x180 [<0000000070490868>] .blocking_notifier_call_chain+0x64/0x90 [<00000000131d8149>] .wf_thread_func+0x114/0x1a0 [<000000000d54838d>] .kthread+0x13c/0x190 [<00000000669b72bc>] .ret_from_kernel_thread+0x58/0x64
Fix it by rearranging the logic so we deal with each buffer separately, which then makes it easy to free the buffer once we're done with it.
Fixes: ac171c46667c ("[PATCH] powerpc: Thermal control for dual core G5s") Cc: stable@vger.kernel.org # v2.6.16+ Reported-by: Erhard F. erhard_f@mailbox.org Signed-off-by: Michael Ellerman mpe@ellerman.id.au Tested-by: Erhard F. erhard_f@mailbox.org Link: https://lore.kernel.org/r/20200423060038.3308530-1-mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/macintosh/windfarm_pm112.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-)
--- a/drivers/macintosh/windfarm_pm112.c +++ b/drivers/macintosh/windfarm_pm112.c @@ -132,14 +132,6 @@ static int create_cpu_loop(int cpu) s32 tmax; int fmin;
- /* Get PID params from the appropriate SAT */ - hdr = smu_sat_get_sdb_partition(chip, 0xC8 + core, NULL); - if (hdr == NULL) { - printk(KERN_WARNING"windfarm: can't get CPU PID fan config\n"); - return -EINVAL; - } - piddata = (struct smu_sdbp_cpupiddata *)&hdr[1]; - /* Get FVT params to get Tmax; if not found, assume default */ hdr = smu_sat_get_sdb_partition(chip, 0xC4 + core, NULL); if (hdr) { @@ -152,6 +144,16 @@ static int create_cpu_loop(int cpu) if (tmax < cpu_all_tmax) cpu_all_tmax = tmax;
+ kfree(hdr); + + /* Get PID params from the appropriate SAT */ + hdr = smu_sat_get_sdb_partition(chip, 0xC8 + core, NULL); + if (hdr == NULL) { + printk(KERN_WARNING"windfarm: can't get CPU PID fan config\n"); + return -EINVAL; + } + piddata = (struct smu_sdbp_cpupiddata *)&hdr[1]; + /* * Darwin has a minimum fan speed of 1000 rpm for the 4-way and * 515 for the 2-way. That appears to be overkill, so for now, @@ -174,6 +176,9 @@ static int create_cpu_loop(int cpu) pid.min = fmin;
wf_cpu_pid_init(&cpu_pid[cpu], &pid); + + kfree(hdr); + return 0; }