The change is similar to that is used in comp_algorithm_set. This is detected by KASAN.
================================================================== Unable to handle kernel paging request at virtual address ffffffffc1edc3c8 KASAN: maybe wild-memory-access in range [0x0003fffe0f6e1e40-0x0003fffe0f6e1e47] Mem abort info: ESR = 0x0000000096000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x06: level 2 translation fault Data abort info: ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 swapper pgtable: 4k pages, 48-bit VAs, pgdp=00000000427dc000 [ffffffffc1edc3c8] pgd=00000000430e7003, p4d=00000000430e7003, pud=00000000430e8003, pmd=0000000000000000 Internal error: Oops: 0000000096000006 [#1] SMP
Tainted: [W]=WARN, [C]=CRAP, [N]=TEST Hardware name: Pine64 PinePhone (1.2) (DT) pstate: a0000005 (NzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : kfree+0x60/0x3a0 lr : zram_destroy_comps+0x98/0x198 [zram] sp : ffff800089b57450 x29: ffff800089b57460 x28: 0000000000000004 x27: ffff800082833010 x26: 1fffe00000c8039c x25: 1fffe00000ba5004 x24: ffff000005d28000 x23: ffff800082533178 x22: ffff80007b71eaa8 x21: ffff000006401ce8 x20: ffff80007b70f7a0 x19: ffffffffc1edc3c0 x18: 1ffff00010506d6b x17: 0000000000000000 x16: 0000000000000000 x15: ffff8000808e85e4 x14: ffff8000808e8478 x13: ffff80008003fa50 x12: ffff80008003f87c x11: ffff800080011550 x10: ffff800081ee63f0 x9 : ffff80007b71eaa8 x8 : ffff80008003fa50 x7 : ffff80008003f87c x6 : 00000018a10e2f30 x5 : 00ffffffffffffff x4 : ffff00000ec93200 x3 : ffff00000bbee6e0 x2 : 0000000000000000 x1 : 0000000000000000 x0 : fffffdffc0000000
Call trace: kfree+0x60/0x3a0 zram_destroy_comps+0x98/0x198 [zram] zram_reset_device+0x22c/0x4a8 [zram] reset_store+0x1bc/0x2d8 [zram] dev_attr_store+0x44/0x80 sysfs_kf_write+0xfc/0x188 kernfs_fop_write_iter+0x28c/0x428 vfs_write+0x4dc/0x9b8 ksys_write+0x100/0x1f8 __arm64_sys_write+0x74/0xb8 invoke_syscall+0xd8/0x260 el0_svc_common.constprop.0+0xb4/0x240 do_el0_svc+0x48/0x68 el0_svc+0x40/0xc8 el0t_64_sync_handler+0x120/0x130 el0t_64_sync+0x190/0x198 Code: b26287e0 d34cfe73 f2dfbfe0 8b131813 (f9400660) ==================================================================
Signed-off-by: Andrey Skvortsov andrej.skvortzov@gmail.com Fixes: 684826f8271a ("zram: free secondary algorithms names") Cc: stable@vger.kernel.org --- drivers/block/zram/zram_drv.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index c3d245617083d..d9d2c36658f59 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -2116,7 +2116,9 @@ static void zram_destroy_comps(struct zram *zram) }
for (prio = ZRAM_SECONDARY_COMP; prio < ZRAM_MAX_COMPS; prio++) { - kfree(zram->comp_algs[prio]); + /* Do not free statically defined compression algorithms */ + if (zram->comp_algs[prio] != default_compressor) + kfree(zram->comp_algs[prio]); zram->comp_algs[prio] = NULL; }