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authorAnders Roxell <anders.roxell@linaro.org>2022-12-06 11:34:16 +0300
committerDamien Le Moal <damien.lemoal@opensource.wdc.com>2022-12-07 02:36:37 +0300
commitd95d140e83634e7914277862dee841564d02879f (patch)
treefd1df87847346c7119bb81c0e466cff5285c4a9a /drivers/ata
parente20e81a24a4d58744a29715aac2f795cd1651955 (diff)
downloadlinux-d95d140e83634e7914277862dee841564d02879f.tar.xz
ata: libahci_platform: ahci_platform_find_clk: oops, NULL pointer
When booting a arm 32-bit kernel with config CONFIG_AHCI_DWC enabled on a am57xx-evm board. This happens when the clock references are unnamed in DT, the strcmp() produces a NULL pointer dereference, see the following oops, NULL pointer dereference: [ 4.673950] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 4.682098] [00000000] *pgd=00000000 [ 4.685699] Internal error: Oops: 5 [#1] SMP ARM [ 4.690338] Modules linked in: [ 4.693420] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.1.0-rc7 #1 [ 4.699615] Hardware name: Generic DRA74X (Flattened Device Tree) [ 4.705749] PC is at strcmp+0x0/0x34 [ 4.709350] LR is at ahci_platform_find_clk+0x3c/0x5c [ 4.714416] pc : [<c130c494>] lr : [<c0c230e0>] psr: 20000013 [ 4.720703] sp : f000dda8 ip : 00000001 fp : c29b1840 [ 4.725952] r10: 00000020 r9 : c1b23380 r8 : c1b23368 [ 4.731201] r7 : c1ab4cc4 r6 : 00000001 r5 : c3c66040 r4 : 00000000 [ 4.737762] r3 : 00000080 r2 : 00000080 r1 : c1ab4cc4 r0 : 00000000 [...] [ 4.998870] strcmp from ahci_platform_find_clk+0x3c/0x5c [ 5.004302] ahci_platform_find_clk from ahci_dwc_probe+0x1f0/0x54c [ 5.010589] ahci_dwc_probe from platform_probe+0x64/0xc0 [ 5.016021] platform_probe from really_probe+0xe8/0x41c [ 5.021362] really_probe from __driver_probe_device+0xa4/0x204 [ 5.027313] __driver_probe_device from driver_probe_device+0x38/0xc8 [ 5.033782] driver_probe_device from __driver_attach+0xb4/0x1ec [ 5.039825] __driver_attach from bus_for_each_dev+0x78/0xb8 [ 5.045532] bus_for_each_dev from bus_add_driver+0x17c/0x220 [ 5.051300] bus_add_driver from driver_register+0x90/0x124 [ 5.056915] driver_register from do_one_initcall+0x48/0x1e8 [ 5.062591] do_one_initcall from kernel_init_freeable+0x1cc/0x234 [ 5.068817] kernel_init_freeable from kernel_init+0x20/0x13c [ 5.074584] kernel_init from ret_from_fork+0x14/0x2c [ 5.079681] Exception stack(0xf000dfb0 to 0xf000dff8) [ 5.084747] dfa0: 00000000 00000000 00000000 00000000 [ 5.092956] dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 5.101165] dfe0: 00000000 00000000 00000000 00000000 00000013 00000000 [ 5.107818] Code: e5e32001 e3520000 1afffffb e12fff1e (e4d03001) [ 5.114013] ---[ end trace 0000000000000000 ]--- Add an extra check in the if-statement if hpriv-clks[i].id. Fixes: 6ce73f3a6fc0 ("ata: libahci_platform: Add function returning a clock-handle by id") Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Reviewed-by: Serge Semin <fancer.lancer@gmail.com> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Diffstat (limited to 'drivers/ata')
-rw-r--r--drivers/ata/libahci_platform.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
index ddf17e2d266c..b9e336bacf17 100644
--- a/drivers/ata/libahci_platform.c
+++ b/drivers/ata/libahci_platform.c
@@ -109,7 +109,7 @@ struct clk *ahci_platform_find_clk(struct ahci_host_priv *hpriv, const char *con
int i;
for (i = 0; i < hpriv->n_clks; i++) {
- if (!strcmp(hpriv->clks[i].id, con_id))
+ if (hpriv->clks[i].id && !strcmp(hpriv->clks[i].id, con_id))
return hpriv->clks[i].clk;
}