# CVE-2021-47440: linux: In the Linux kernel, the following vulnerability has been resolved:  net: encx24j600: check error in devm_regmap_init...

CVE-2021-47440 is fixed in linux on 1 platform, first by DEBIAN-CVE-2021-47440, released May 22, 2024. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2021-47440
- Priority: Routine
- CVSS: 2.3 (low)
- EPSS: 0.0022
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 22, 2024

## Description

In the Linux kernel, the following vulnerability has been resolved:  net: encx24j600: check error in devm_regmap_init_encx24j600  devm_regmap_init may return error which caused by like out of memory, this will results in null pointer dereference later when reading or writing register:  general protection fault in encx24j600_spi_probe KASAN: null-ptr-deref in range [0x0000000000000090-0x0000000000000097] CPU: 0 PID: 286 Comm: spi-encx24j600- Not tainted 5.15.0-rc2-00142-g9978db750e31-dirty #11 9c53a778c1306b1b02359f3c2bbedc0222cba652 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:regcache_cache_bypass drivers/base/regmap/regcache.c:540 Code: 54 41 89 f4 55 53 48 89 fb 48 83 ec 08 e8 26 94 a8 fe 48 8d bb a0 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 4a 03 00 00 4c 8d ab b0 00 00 00 48 8b ab a0 00 RSP: 0018:ffffc900010476b8 EFLAGS: 00010207 RAX: dffffc0000000000 RBX: fffffffffffffff4 RCX: 0000000000000000 RDX: 0000000000000012 RSI: ffff888002de0000 RDI: 0000000000000094 RBP: ffff888013c9a000 R08: 0000000000000000 R09: fffffbfff3f9cc6a R10: ffffc900010476e8 R11: fffffbfff3f9cc69 R12: 0000000000000001 R13: 000000000000000a R14: ffff888013c9af54 R15: ffff888013c9ad08 FS:  00007ffa984ab580(0000) GS:ffff88801fe00000(0000) knlGS:0000000000000000 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a6384136c8 CR3: 000000003bbe6003 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace:  encx24j600_spi_probe drivers/net/ethernet/microchip/encx24j600.c:459  spi_probe drivers/spi/spi.c:397  really_probe drivers/base/dd.c:517  __driver_probe_device drivers/base/dd.c:751  driver_probe_device drivers/base/dd.c:782  __device_attach_driver drivers/base/dd.c:899  bus_for_each_drv drivers/base/bus.c:427  __device_attach drivers/base/dd.c:971  bus_probe_device drivers/base/bus.c:487  device_add drivers/base/core.c:3364  __spi_add_device drivers/spi/spi.c:599  spi_add_device drivers/spi/spi.c:641  spi_new_device drivers/spi/spi.c:717  new_device_store+0x18c/0x1f1 [spi_stub 4e02719357f1ff33f5a43d00630982840568e85e]  dev_attr_store drivers/base/core.c:2074  sysfs_kf_write fs/sysfs/file.c:139  kernfs_fop_write_iter fs/kernfs/file.c:300  new_sync_write fs/read_write.c:508 (discriminator 4)  vfs_write fs/read_write.c:594  ksys_write fs/read_write.c:648  do_syscall_64 arch/x86/entry/common.c:50  entry_SYSCALL_64_after_hwframe arch/x86/entry/entry_64.S:113  Add error check in devm_regmap_init_encx24j600 to avoid this situation.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 5.14.16-1 | [DEBIAN-CVE-2021-47440](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47440.md) | May 22, 2024 |
| Linux | linux Debian 13.5 (trixie) | 5.14.16-1 | [DEBIAN-CVE-2021-47440](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47440.md) | May 22, 2024 |
| Linux | linux Debian 14 | 5.14.16-1 | [DEBIAN-CVE-2021-47440](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47440.md) | May 22, 2024 |

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